Organic light-emitting device and electronic apparatus including same

ABSTRACT

Provided is an organic light-emitting device including: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode and including an emission layer, wherein the emission layer may include a host and a dopant, the host may include a first compound and a second compound different from the first compound, the dopant may include a third compound and a fourth compound different from the third compound, and the third compound may be a platinum-containing organometallic compound.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication No. 10-2020-0054777, filed on May 7, 2020, in the KoreanIntellectual Property Office, the entire content of which is herebyincorporated by reference.

BACKGROUND 1. Field

One or more embodiments of the present disclosure relate to an organiclight-emitting device and an electronic apparatus including the organiclight-emitting device.

2. Description of Related Art

Organic light-emitting devices (OLEDs) are self-emissive devices that,as compared with other devices of the related art, have wide viewingangles, high contrast ratios, short response times, and excellentcharacteristics in terms of brightness, driving voltage, and responsespeed, and produce full-color images.

OLEDs may include a first electrode on a substrate, and a hole transportregion, an emission layer, an electron transport region, and a secondelectrode sequentially stacked on the first electrode. Holes providedfrom the first electrode may move toward the emission layer through thehole transport region, and electrons provided from the second electrodemay move toward the emission layer through the electron transportregion. Carriers, such as holes and electrons, recombine in the emissionlayer to produce excitons. These excitons transit (e.g., transition orrelax) from an excited state to a ground state to thereby generatelight.

SUMMARY

One or more embodiments relate to an organic light-emitting devicehaving high color purity, high efficiency, and long lifespan and anelectronic apparatus including the organic light-emitting device.

Additional aspects of embodiments will be set forth in part in thedescription which follows and, in part, will be apparent from thedescription, or may be learned by practice of the presented embodimentsof the disclosure.

According to one or more embodiments, an organic light-emitting devicemay include:

a first electrode,

a second electrode facing the first electrode, and

an organic layer between the first electrode and the second electrodeand including an emission layer,

wherein the emission layer may include a host and a dopant,

the host may include a first compound and a second compound differentfrom the first compound,

the dopant may include a third compound and a fourth compound differentfrom the third compound, and

the third compound may be a platinum-containing organometallic compound.

According to one or more embodiments, an electronic apparatus mayinclude a thin-film transistor including a source electrode, a drainelectrode, and an active layer; and the organic light-emitting device,wherein the first electrode of the organic light-emitting device may beelectrically coupled to any one selected from the source electrode andthe drain electrode of the thin-film transistor.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of certain embodiments of thedisclosure will be more apparent from the following description taken inconjunction with the accompanying drawings, in which:

FIG. 1 is a schematic cross-sectional view of an embodiment of anorganic light-emitting device;

FIG. 2 is a schematic cross-sectional view of an embodiment of anorganic light-emitting device;

FIG. 3 is a schematic cross-sectional view of an embodiment of anorganic light-emitting device; and

FIG. 4 is a schematic cross-sectional view of an embodiment of anorganic light-emitting device.

DETAILED DESCRIPTION

Reference will now be made in more detail to embodiments of the presentdisclosure, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to like elementsthroughout. In this regard, the present embodiments may have differentforms and should not be construed as being limited to the descriptionsset forth herein. Accordingly, the embodiments are merely describedbelow, by referring to the figures, to explain aspects of embodiments ofthe present description. As used herein, the term “and/or” includes anyand all combinations of one or more of the associated listed items.Throughout the disclosure, the expression “at least one of a, b or c”indicates only a, only b, only c, both a and b, both a and c, both b andc, all of a, b, and c, or variations thereof.

As the present disclosure allows for various changes and numerousembodiments, particular embodiments will be illustrated in the drawingsand described in more detail in the written description. Effects,features, and a method of providing the subject matter of the presentdisclosure will be readily apparent to those of ordinary skill in theart by referring to example embodiments of the present disclosure withreference to the attached drawings. The subject matter of the presentdisclosure may, however, be embodied in many different forms and shouldnot be construed as being limited to the embodiments set forth herein.

Hereinafter, the subject matter of the present disclosure will bedescribed in more detail by explaining example embodiments of thepresent disclosure with reference to the attached drawings. Likereference numerals in the drawings denote like elements, and thus,duplicative description thereof will not be repeated.

In the embodiments described in the present specification, an expressionused in the singular encompasses the expression of the plural, unless ithas a clearly different meaning in the context.

In the present specification, it is to be understood that the terms suchas “including,” “having,” and “comprising” are intended to indicate theexistence of the features or components disclosed in the specification,and are not intended to preclude the possibility that one or more otherfeatures or components may exist or may be added.

It will be understood that when a layer, region, or component isreferred to as being “on” or “onto” another layer, region, or component,it may be directly or indirectly formed over the other layer, region, orcomponent. That is, for example, intervening layers, regions, orcomponents may be present.

Sizes of components in the drawings may be exaggerated for convenienceof explanation. In other words, because sizes and thicknesses ofcomponents in the drawings may be arbitrarily illustrated forconvenience of explanation, the following embodiments are not limitedthereto.

The term “organic layer,” as used herein, refers to a single and/or aplurality of layers between an anode and a cathode in an organiclight-emitting device. A material included in the “organic layer” is notlimited to an organic material. For example, the organic layer mayinclude an inorganic material.

As used herein, the expression the “(organic layer) includes a compoundrepresented by Formula N” (wherein N indicates an arbitrary integer) maybe construed as meaning the “(organic layer) may include one compoundthat is represented by Formula N or two different compounds that arerepresented by Formula N.”

The subject matter of the present disclosure will now be described morefully with reference to the accompanying drawings, in which exemplaryembodiments of the present disclosure are shown.

Description of FIG. 1

FIG. 1 is a schematic view of an organic light-emitting device 10according to an exemplary embodiment. An organic light-emitting device10 includes a first electrode 110; a second electrode 190 facing thefirst electrode 110; and an emission layer 150 between the firstelectrode 110 and the second electrode 190 and including an organiclayer 150.

The emission layer may include a host and a dopant, the host may includea first compound and a second compound different from the firstcompound, the dopant may include a third compound and a fourth compounddifferent from the third compound, and the third compound may be aplatinum-containing organometallic compound.

As the organic light-emitting device 10 includes two different types ofhosts as co-hosts in the emission layer thereof, balance between holesand electrons in the emission layer may be improved. In addition, thethird compound may improve the color purity of light emitted from theorganic light-emitting device 10 and luminescence efficiency of theorganic light-emitting device 10, and the fourth compound may improvelifespan of the organic light-emitting device 10. Accordingly, as theorganic light-emitting device 10 includes the third compound and thefourth compound as co-dopants, the color purity, efficiency, andlifespan characteristics may be improved.

First Electrode 110

In FIG. 1, a substrate may be additionally located under the firstelectrode 110 or above the second electrode 190. The substrate may be aglass substrate and/or a plastic substrate, each having excellentmechanical strength, thermal stability, transparency, surfacesmoothness, ease of handling, and water resistance.

The first electrode 110 may be formed by depositing and/or sputtering,onto the substrate, a material for forming the first electrode 110. Whenthe first electrode 110 is an anode, the material for forming the firstelectrode 110 may be selected from materials having a high work functionthat facilitate hole injection.

The first electrode 110 may be a reflective electrode, asemi-transmissive electrode, or a transmissive electrode. When the firstelectrode 110 is a transmissive electrode, a material for forming thefirst electrode 110 may be selected from indium tin oxide (ITO), indiumzinc oxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), and anycombinations thereof, but the present disclosure is not limited thereto.In some embodiments, when the first electrode 110 is a semi-transmissiveelectrode or a reflective electrode, as a material for forming the firstelectrode 110, at least one selected from magnesium (Mg), silver (Ag),aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium(Mg—In), magnesium-silver (Mg—Ag), and any combination thereof may beused, but the present disclosure is not limited thereto.

The first electrode 110 may have a single-layered structure, or amulti-layered structure including two or more layers. In someembodiments, the first electrode 110 may have a triple-layered structureof ITO/Ag/ITO, but the present disclosure is not limited thereto.

Emission Layer in Organic Layer 150

The emission layer may include a host and a dopant, the host may includea first compound and a second compound different from the firstcompound, the dopant may include a third compound and a fourth compounddifferent from the third compound.

According to one or more embodiments, the first compound and the secondcompound may be hosts that each transport different types of charge(holes or electrons).

In some embodiments, the first compound may be a hole-transporting host,and the second compound may be an electron-transporting host.

First Compound

In some embodiments, the first compound may be a compound including atleast one hole-transporting moiety. In some embodiments, thehole-transporting moiety may include a carbazole group, a dibenzofurangroup, a dibenzothiophene group, a dibenzosilole group, and/or an aminegroup, but the present disclosure is not limited thereto.

According to one or more embodiments, the first compound may include atleast one moiety represented by any one selected from Formulae 3-1 to3-3:

wherein, in Formulae 3-1 to 3-3,

X₃₁ may be selected from O, S, N-(L₃₃)_(a33)-(R₃₃)_(b33), C(R₃₃)(R₃₄),and Si(R₃₃)(R₃₄),

CY₃₁ and CY₃₂ may each independently be a π-electron rich cyclic group,and

*, *′, and *″ each indicate a binding site to an adjacent atom.

The term “π-electron rich cyclic group,” as used herein, refers to acarbocyclic or heterocyclic group not including *═N—*′ as a ring-formingmoiety.

In some embodiments, the “π-electron rich cyclic group” may be a benzenegroup, a heptalene group, an indene group, a naphthalene group, anazulene group, a heptalene group, an indacene group, an acenaphthylenegroup, a fluorene group, a spiro-bifluorene group, a benzofluorenegroup, a dibenzofluorene group, a phenalene group, a phenanthrene group,an anthracene group, a fluoranthene group, a triphenylene group, apyrene group, a chrysene group, a naphthacene group, a picene group, aperylene group, a pentacene group, a hexacene group, a pentaphene group,a rubicene group, a coronene group, an ovalene group, a pyrrole group, afuran group, a thiophene group, an isoindole group, an indole group, anindene group, a benzofuran group, a benzothiophene group, a benzosilolegroup, a naphthopyrrole group, a naphthofuran group, a naphthothiophenegroup, a naphthosilole group, a benzocarbazole group, a dibenzocarbazolegroup, a dibenzofuran group, a dibenzothiophene group, adibenzothiophene sulfone group, a carbazole group, a dibenzosilolegroup, an indenocarbazole group, an indolocarbazole group, abenzofurocarbazole group, a benzothienocarbazole group, abenzosilolocarbazole group, a triindolobenzene group, an acridine group,a dihydroacridine group, a benzonaphthofuran group, abenzonapthothiophene group, an indolophenanthrene group, abenzofuranophenanthrene group, or a benzothienophenanthrene group, butthe present disclosure is not limited thereto.

According to one or more embodiments, CY₃₁ and CY₃₂ in Formulae 3-1 to3-3 may each independently be a benzene group, a naphthalene group, aphenanthrene group, a fluorene group, a carbazole group, a dibenzofurangroup, a dibenzothiophene group, or a dibenzosilole group.

According to one or more embodiments, the first compound may be ahole-transporting host including at least one moiety represented by anyone selected from Formulae 3-1 to 3-3, as shown herein above.

According to one or more embodiments, the first compound may be selectedfrom compounds represented by Formulae 3-11 to 3-14:

wherein, in Formula 3-11,

CY₃₁ and ring CY₃₂ may each independently be a π-electron rich cyclicgroup having 3 to 30 carbon atoms,

X₃₁ may be selected from O, S, N-(L₃₃)_(a33)-(R₃₃)_(b33), C(R₃₃)(R₃₄),and Si(R₃₃)(R₃₄),

c31 and c32 may each independently be an integer from 0 to 3,

wherein, in Formulae 3-11 to 3-14,

L₃₁ to L₃₃ and L₄₁ to L₄₇ may each independently be selected from asingle bond, a substituted or unsubstituted C₅-C₃₀ carbocyclic group (ora substituted or unsubstituted C₄-C₃₀ carbocyclic group), and asubstituted or unsubstituted C₁-C₃₀ heterocyclic group,

a31 to a33 and a41 to a47 may each independently be an integer from 1 to10,

R₃₁ to R₃₄ and R₄₁ to R₄₇ may each independently be selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amidino group, a hydrazino group, a hydrazono group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and—P(═O)(Q₁)(Q₂),

b31 to b33 and b41 to b46 may each independently be an integer from 1 to10, and

at least one substituent of the substituted C₅-C₃₀ carbocyclic group (orthe substituted or unsubstituted C₄-C₃₀ carbocyclic group), thesubstituted C₁-C₃₀ heterocyclic group, the substituted C₁-C₃₀ alkylgroup, the substituted C₂-C₃₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₁-C₆₀ heteroaryl group, the substituted monovalentnon-aromatic condensed polycyclic group, and the substituted monovalentnon-aromatic condensed heteropolycyclic group may be selected from:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆₀ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),—S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may eachindependently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amino group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₆ alkyl group, aC₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, aC₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group.

According to one or more embodiments, in Formula 3-11, CY₃₁ and CY₃₂ mayeach independently be selected from a benzene group, a naphthalenegroup, an anthracene group, a phenanthrene group, a fluoranthene group,a triphenylene group, a pyrene group, a chrysene group, an indene group,a fluorene group, a spiro-bifluorene group, a benzofluorene group, adibenzofluorene group, a carbazole group, a benzocarbazole group, adibenzocarbazole group, a dibenzosilole group, a dibenzofuran group, anda dibenzothiophene group.

In some embodiments, CY₃₁ and CY₃₂ may each independently be selectedfrom a benzene group, a naphthalene group, a phenanthrene group, afluorene group, a carbazole group, a dibenzosilole group, a dibenzofurangroup, and a dibenzothiophene group.

According to one or more embodiments, in Formulae 3-11 to 3-14,

L₃₁ to L₃₃ and L₄₁ to L₄₇ may each independently be a single bond or asubstituted or unsubstituted π-electron rich cyclic group having 3 to 30carbon atoms.

In some embodiments, L₃₁ to L₃₃ and L₄₁ to L₄₇ may each independently beselected from:

a single bond, a benzene group, a heptalene group, an indene group, anaphthalene group, an azulene group, a heptalene group, an indacenegroup, an acenaphthylene group, a fluorene group, a spiro-bifluorenegroup, a benzofluorene group, a dibenzofluorene group, a phenalenegroup, a phenanthrene group, an anthracene group, a fluoranthene group,a triphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentacene group, a hexacenegroup, a pentacene group, a rubicene group, a coronene group, an ovalenegroup, a pyrrole group, an isoindole group, an indole group, a furangroup, a thiophene group, a benzofuran group, a benzothiophene group, abenzosilole group, a benzocarbazole group, a dibenzocarbazole group, adibenzofuran group, a dibenzothiophene group, a dibenzothiophene sulfonegroup, a carbazole group, a dibenzosilole group, an indenocarbazolegroup, an indolocarbazole group, a benzofurocarbazole group, abenzothienocarbazole group, a benzosilolocarbazole group, atriindolobenzene group, an acridine group, and a dihydroacridine group;and

a benzene group, a heptalene group, an indene group, a naphthalenegroup, an azulene group, a heptalene group, an indacene group, anacenaphthylene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentacene group, a hexacenegroup, a pentacene group, a rubicene group, a coronene group, an ovalenegroup, a pyrrole group, an isoindole group, an indole group, a furangroup, a thiophene group, a benzofuran group, a benzothiophene group, abenzosilole group, a benzocarbazole group, a dibenzocarbazole group, adibenzofuran group, a dibenzothiophene group, a dibenzothiophene sulfonegroup, a carbazole group, a dibenzosilole group, an indenocarbazolegroup, an indolocarbazole group, a benzofurocarbazole group, abenzothienocarbazole group, a benzosilolocarbazole group, atriindolobenzene group, an acridine group, and a dihydroacridine group,each substituted with deuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxygroup, a phenyl group, a naphthyl group, a fluorenyl group, a carbazolylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, atriphenylenyl group, a biphenyl group, and a terphenyl group.

In Formulae 3-11 to 3-14, a31 to a33 and a41 to a47 may respectivelyindicate the number of L₃₁ to L₃₃ and L₄₁ to L₄₇, and a31 to a33 and a41to a47 may each independently an integer from 1 to 10.

According to one or more embodiments, in Formulae 3-11 to 3-14, R₃₁ toR₃₄ and R₄₁ to R₄₆ may each independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a cyano group, aphenyl group, and a biphenyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a spiro-fluorene-benzofluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a pyrenyl group, aphenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, a silolyl group, an imidazolyl group,a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, apyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolylgroup, an indazolyl group, a purinyl group, a quinolinyl group, anisoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, a benzosilolyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, adibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinylgroup, an imidazopyrimidinyl group, an oxazolopyridinyl group, athiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenylgroup, an azaspiro-bifluorenyl group, an azacarbazolyl group, anazadibenzofuranyl group, an azadibenzothiophenyl group, anazadibenzosilolyl group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), and —B(Q₁)(Q₂);and

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a spiro-fluorene-benzofluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a pyrenyl group, aphenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, a silolyl group, an imidazolyl group,a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, apyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolylgroup, an indazolyl group, a purinyl group, a quinolinyl group, anisoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, a benzosilolyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, adibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinylgroup, an imidazopyrimidinyl group, an oxazolopyridinyl group, athiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenylgroup, an azaspiro-bifluorenyl group, an azacarbazolyl group, anazadibenzofuranyl group, an azadibenzothiophenyl group, and anazadibenzosilolyl group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, acyclohexyl group, a cycloheptyl group, a cyclopentenyl group, acyclohexenyl group, a phenyl group, a naphthyl group, a fluorenyl group,a spiro-bifluorenyl group, a spiro-fluorene-benzofluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a pyrenyl group, aphenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, a silolyl group, an imidazolyl group,a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, apyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolylgroup, an indazolyl group, a purinyl group, a quinolinyl group, anisoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, a benzosilolyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, adibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinylgroup, an imidazopyrimidinyl group, an oxazolopyridinyl group, athiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenylgroup, an azaspiro-bifluorenyl group, an azacarbazolyl group, anazadibenzofuranyl group, an azadibenzothiophenyl group, anazadibenzosilolyl group, a biphenyl group, and a terphenyl group,

wherein Q₁ to Q₃ may each independently be selected from hydrogen,deuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group,a naphthyl group, a fluorenyl group, a carbazolyl group, adibenzofuranyl group, a dibenzothiophenyl group, a triphenylenyl group,a biphenyl group, a terphenyl group, and a tetraphenyl group.

In some embodiments, in Formulae 3-11 to 3-14, R₃₃ and R₄₁ to R₄₆ mayeach independently be selected from hydrogen, a substituted orunsubstituted monovalent π-electron rich cyclic group, —Si(Q₁)(Q₂)(Q₃),and —N(Q₁)(Q₂),

wherein Q₁ to Q₃ may each independently be selected from hydrogen,deuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a π-electronrich cyclic group, a biphenyl group, and a terphenyl group.

In some embodiments, R₃₃ and R₄₁ to R₄₆ may each independently beselected from:

a phenyl group, a biphenyl group, a terphenyl group, a tetraphenylgroup, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a pyrrolyl group, an isoindolyl group, an indolylgroup, a furanyl group, a thiophenyl group, a benzofuranyl group, abenzothiophenyl group, a benzosilolyl group, a dibenzofuranyl group, adibenzothiophenyl group, a carbazolyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, an indenocarbazolylgroup, an indolocarbazolyl group, a benzofurocarbazolyl group, abenzothienocarbazolyl group, a benzosilolocarbazolyl group, an acridinylgroup, and a dihydroacridinyl group;

a phenyl group, a biphenyl group, a terphenyl group, a tetraphenylgroup, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a pyrrolyl group, an isoindolyl group, an indolylgroup, a furanyl group, a thiophenyl group, a benzofuranyl group, abenzothiophenyl group, a benzosilolyl group, a dibenzofuranyl group, adibenzothiophenyl group, a carbazolyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, an indenocarbazolylgroup, an indolocarbazolyl group, a benzofurocarbazolyl group, abenzothienocarbazolyl group, a benzosilolocarbazolyl group, an acridinylgroup, and a dihydroacridinyl group, each substituted with at least oneselected from deuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, aphenyl group, a naphthyl group, a fluorenyl group, a carbazolyl group, adibenzofuranyl group, a dibenzothiophenyl group, a triphenylenyl group,a biphenyl group, and a terphenyl group;

—Si(Q₁)(Q₂)(Q₃) and —N(Q₁)(Q₂),

wherein Q₁ to Q₃ may each independently be selected from hydrogen,deuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group,a naphthyl group, a fluorenyl group, a carbazolyl group, adibenzofuranyl group, a dibenzothiophenyl group, a triphenylenyl group,a biphenyl group, and a terphenyl group.

b31 to b33 and b41 to b46 may respectively indicate the number of R₃₁(s)to R₃₃(s) and R₄₁(s) to R₄₆(s), and b31 to b33 and b41 to b46 may eachindependently be an integer from 1 to 10.

According to one or more embodiments, the first compound may be selectedfrom the following compounds, but the present disclosure is not limitedthereto:

Second Compound

The second compound may include at least one electron-transportingmoiety. In some embodiments, the second compound may include anelectron-transporting moiety including at least one selected from —F, acyano group, a C₁-C₆₀ alkyl group substituted with —F or a cyano group,a C₆-C₆₀ aryl group substituted with —F or a cyano group, and aπ-electron-depleted nitrogen-containing cyclic group.

In some embodiments, the second compound may be represented by Formula4-1:

wherein, in Formula 4-1,

X₅₁ may be N or C[(L₅₄)_(a54)-(R₅₄)_(b54)], X₅₂ may be N orC[(L₅₅)_(a55)-(R₅₅)_(b55)], and X₅₃ may be N orC[(L₅₆)_(a56)-(R₅₆)_(b56)],

L₅₁ to L₅₆ may each independently be selected from a single bond, asubstituted or unsubstituted C₅-C₃₀ carbocyclic group (or a substitutedor unsubstituted C₄-C₃₀ carbocyclic group) and a substituted orunsubstituted C₁-C₃₀ heterocyclic group,

a51 to a56 may each independently be an integer from 1 to 10,

R₅₁ to R₅₆ may each independently be selected from hydrogen, deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazino group, a hydrazono group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂),—B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂),

b51 to b56 may each independently be an integer from 1 to 10, and

at least one substituent of the substituted C₅-C₃₀ carbocyclic group (orthe substituted or unsubstituted C₄-C₃₀ carbocyclic group), thesubstituted C₁-C₃₀ heterocyclic group, the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₁-C₆₀ heteroaryl group, the substituted monovalentnon-aromatic condensed polycyclic group, and the substituted monovalentnon-aromatic condensed heteropolycyclic group may be selected from theaforementioned substituents.

According to one or more embodiments, in Formula 4-1, L₅₁ to L₅₆ mayeach independently be selected from: a single bond, a benzene group, anaphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, adibenzofuran group, a dibenzothiophene group, a carbazole group, animidazole group, a pyrazole group, a thiazole group, an isothiazolegroup, an oxazole group, an isoxazole group, a pyridine group, apyrazine group, a pyridazine group, a pyrimidine group, an indazolegroup, a purine group, a quinoline group, an isoquinoline group, abenzoquinoline group, a benzoisoquinoline group, a phthalazine group, anaphthyridine group, a quinoxaline group, a benzoquinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, aphenanthroline group, a phenazine group, a benzimidazole group, anisobenzothiazole group, a benzoxazole group, an isobenzoxazole group, atriazole group, a tetrazole group, an oxadiazole group, a triazinegroup, a thiadiazole group, an imidazopyridine group, animidazopyrimidine group, an azaindene group, an azaindole group, anazabenzofuran group, an azabenzothiophene group, an azabenzosilolegroup, an azafluorene group, an azacarbazole group, an azadibenzofurangroup, an azadibenzothiophene group, and an azadibenzosilole group; and

a benzene group, a naphthalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, a dibenzofuran group, a dibenzothiophene group, acarbazole group, an imidazole group, a pyrazole group, a thiazole group,an isothiazole group, an oxazole group, an isoxazole group, a pyridinegroup, a pyrazine group, a pyridazine group, a pyrimidine group, anindazole group, a purine group, a quinoline group, an isoquinolinegroup, a benzoquinoline group, a benzoisoquinoline group, a phthalazinegroup, a naphthyridine group, a quinoxaline group, a benzoquinoxalinegroup, a quinazoline group, a cinnoline group, a phenanthridine group, aphenanthroline group, a phenazine group, a benzimidazole group, anisobenzothiazole group, a benzoxazole group, an isobenzoxazole group, atriazole group, a tetrazole group, an oxadiazole group, a triazinegroup, a thiadiazole group, an imidazopyridine group, animidazopyrimidine group, an azaindene group, an azaindole group, anazabenzofuran group, an azabenzothiophene group, an azabenzosilolegroup, an azafluorene group, an azacarbazole group, an azadibenzofurangroup, an azadibenzothiophene group, and an azadibenzosilole group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a picenyl group, a perylenylgroup, a pentaphenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a carbazolyl group, an imidazolyl group, a pyrazolyl group, athiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolylgroup, a pyridinyl group, a pyrazinyl group, a pyridazinyl group, apyrimidinyl group, an indazolyl group, a purinyl group, a quinolinylgroup, an isoquinolinyl group, a benzoquinolinyl group, abenzoisoquinolinyl group, a phthalazinyl group, a naphthyridinyl group,a quinoxalinyl group, a benzoquinoxalinyl group, a quinazolinyl group, acinnolinyl group, a phenanthridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, abenzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an oxadiazolyl group, a triazinyl group, athiadiazolyl group, an imidazopyridinyl group, an imidazopyrimidinylgroup, an azaindenyl group, an azaindolyl group, an azabenzofuranylgroup, an azabenzothiophenyl group, an azabenzosilolyl group, anazafluorenyl group, an azacarbazolyl group, an azadibenzofuranyl group,an azadibenzothiophenyl group, an azadibenzosilolyl group,—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In some embodiments, in Formula 4-1, R₅₁ to R₅₆ may each independentlybe selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a cyano group, aphenyl group, and a biphenyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a spiro-fluorene-benzofluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a pyrenyl group, aphenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, a silolyl group, an imidazolyl group,a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, apyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolylgroup, an indazolyl group, a purinyl group, a quinolinyl group, anisoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, a benzosilolyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, adibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinylgroup, an imidazopyrimidinyl group, an oxazolopyridinyl group, athiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenylgroup, an azaspiro-bifluorenyl group, an azacarbazolyl group, anazadibenzofuranyl group, an azadibenzothiophenyl group, anazadibenzosilolyl group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), and —B(Q₁)(Q₂);and

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a spiro-fluorene-benzofluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a pyrenyl group, aphenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, a silolyl group, an imidazolyl group,a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, apyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolylgroup, an indazolyl group, a purinyl group, a quinolinyl group, anisoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, a benzosilolyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, adibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinylgroup, an imidazopyrimidinyl group, an oxazolopyridinyl group, athiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenylgroup, an azaspiro-bifluorenyl group, an azacarbazolyl group, anazadibenzofuranyl group, an azadibenzothiophenyl group, and anazadibenzosilolyl group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, acyclohexyl group, a cycloheptyl group, a cyclopentenyl group, acyclohexenyl group, a phenyl group, a naphthyl group, a fluorenyl group,a spiro-bifluorenyl group, a spiro-fluorene-benzofluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a pyrenyl group, aphenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, a silolyl group, an imidazolyl group,a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, apyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolylgroup, an indazolyl group, a purinyl group, a quinolinyl group, anisoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, a benzosilolyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, adibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinylgroup, an imidazopyrimidinyl group, an oxazolopyridinyl group, athiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenylgroup, an azaspiro-bifluorenyl group, an azacarbazolyl group, anazadibenzofuranyl group, an azadibenzothiophenyl group, anazadibenzosilolyl group, a biphenyl group, and a terphenyl group,

wherein Q₁ to Q₃ may each independently be selected from hydrogen,deuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group,a naphthyl group, a fluorenyl group, a carbazolyl group, adibenzofuranyl group, a dibenzothiophenyl group, a triphenylenyl group,a biphenyl group, a terphenyl group, and a tetraphenyl group.

According to one or more embodiments, the second compound may beselected from the following compounds, but the present disclosure is notlimited thereto:

The organic light-emitting device may include mixed hosts of the firstcompound and the second compound. Accordingly, charge balance in anemission layer of the organic light-emitting device may be improved, ascompared with an organic light-emitting device including a single host.In some embodiments, when the first compound and the second compound arehosts that may each transport different types of charge (holes orelectrons), balance of holes and electrons in the emission layer may besuitably maintained, thus improving driving characteristics of theorganic light-emitting device. For example, the exciton profile may beimproved in the emission layer, thus improving efficiency of the organiclight-emitting device.

In some embodiments, a host in the emission layer may include a compoundrepresented by Formula 301:

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21)  Formula 301

wherein, in Formula 301,

Ar₃₀₁ may be selected from a substituted or unsubstituted C₅-C₆₀carbocyclic group (or a substituted or unsubstituted C₄-C₃₀ carbocyclicgroup) and a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xb11 may be 1, 2, or 3,

L₃₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xb1 may be an integer from 0 to 5,

R₃₀₁ may be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂),—B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), and —P(═O)(Q₃₀₁)(Q₃₀₂), and

xb21 may be an integer from 1 to 5,

wherein Q₃₀₁ to Q₃₀₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group, but the present disclosure is notlimited thereto.

In some embodiments, in Formula 301, Ar₃₀₁ may be selected from:

a naphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup; and

a naphthalene group, a fluorene group, a spiro-bifluorene group, abenzofluorene group, a dibenzofluorene group, a phenalene group, aphenanthrene group, an anthracene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a naphthacenegroup, a picene group, a perylene group, a pentaphene group, anindenoanthracene group, a dibenzofuran group, and a dibenzothiophenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group, but the present disclosure is notlimited thereto.

When xb11 in Formula 301 is 2 or greater, at least two Ar₃₀₁(s) may bebound via a single bond.

In one or more embodiments, the compound represented by Formula 301 maybe represented by Formula 301-1 or 301-2:

wherein, in Formulae 301-1 to 301-2,

A₃₀₁ to A₃₀₄ may each independently be selected from a benzene group, anaphthalene group, a phenanthrene group, a fluoranthene group, atriphenylene group, a pyrene group, a chrysene group, a pyridine group,a pyrimidine group, an indene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,an indole group, a carbazole group, a benzocarbazole group, adibenzocarbazole group, a furan group, a benzofuran group, adibenzofuran group, a naphthofuran group, a benzonaphthofuran group, adinaphthofuran group, a thiophene group, a benzothiophene group, adibenzothiophene group, a naphthothiophene group, a benzonapthothiophenegroup, and a dinaphthothiophene group,

X₃₀₁ may be O, S, or N-[(L₃₀₄)_(xb4)-R₃₀₄],

R₃₁₁ to R₃₁₄ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),—B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

xb22 and xb23 may each independently be 0, 1, or 2,

L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃ may respectively be understood byreferring to the descriptions of L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃provided herein,

L₃₀₂ to L₃₀₄ may each be understood by referring to the description ofL₃₀₁ provided herein,

xb2 to xb4 may each be understood by referring to the descriptions ofxb1 provided herein, and

R₃₀₂ to R₃₀₄ may each be understood by referring to the description ofR₃₀₁ provided herein.

In some embodiments, in Formulae 301, 301-1, and 301-2, L₃₀₁ to L₃₀₄ mayeach independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, anaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a thiophenyl group, afuranyl group, a carbazolyl group, an indolyl group, an isoindolylgroup, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, anoxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, abenzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinylgroup, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂),—B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may respectively be understood by referring to thedescriptions of Q₃₁ to Q₃₃ provided herein.

In some embodiments, in Formulae 301, 301-1, and 301-2, R₃₀₁ to R₃₀₄ mayeach independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may respectively be understood by referring to thedescriptions of Q₃₁ to Q₃₃ provided herein.

In some embodiments, the host may include an alkaline earth metalcomplex and/or a zinc (Zn) complex. For example, the host may include aberyllium (Be) complex, e.g., Compound H55, a magnesium (Mg) complex,and/or a zinc (Zn) complex.

In some embodiments, the host may include at least one selected from9,10-di(2-naphthyl)anthracene (ADN),2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN),9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN),4,4′-bis(N-carbazolyl)-1,1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene(mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), and Compounds H1 to H55,but the present disclosure is not limited thereto:

Third Compound and Fourth Compound

According to one or more embodiments, the third compound and the fourthcompound may each independently be an organometallic compoundrepresented by Formula 1:

wherein, in Formulae 1 and 1A to 1C,

M may be selected from a first-row transition metal, a second-rowtransition metal, and a third-row transition metal, wherein M in thethird compound may be platinum (Pt),

L₁ may be selected from represented by a ligand represented by Formula1A, a ligand represented by Formula 1B, and a ligand represented byFormula 1C,

L₂ may be selected from a monodentate ligand, a bidentate ligand, and atridentate ligand,

n1 may be selected from 1, 2, and 3,

n2 may be selected from 0, 1, 2, 3, and 4,

CY₁ to CY₄ may each independently be selected from a C₅-C₃₀ carbocyclicgroup (or a substituted or unsubstituted C₄-C₃₀ carbocyclic group) and aC₁-C₃₀ heterocyclic group,

Y₁ to Y₄ may each independently be selected from a single bond, a doublebond, a substituted or unsubstituted C₆-C₃₀ arylene group, a substitutedor unsubstituted C₁-C₃₀ heteroarylene group, *—O—*′, *—S—*′, *—C(═O)—*′,*—S(═O)—*′, *—C(R₅)(R₆)—*′, *—C(R₅)═C(R₆)—*′, *—C(R₅)═*′,*—Si(R₅)(R₆)—*′, *—B(R₅)—*′, *—N(R₅)—*′, and *—P(R₅)—*′,

a1 to a3 may each independently be selected from 1, 2, and 3,

a4 may be selected from 0, 1, 2, and 3, and when a4 is 0, CY₂ and CY₄may not be connected to each other,

T₁ to T₄ may each independently be selected from a chemical bond (e.g.,a single bond), *—O—*′, *—S—*′, *—B(R₇)—*′, *—N(R₇)—*′, *—P(R₇)—*′,*—C(R₇)(R₈)—*′, *—Si(R₇)(R₈)—*′, *—Ge(R₇)(R₈)—*′, *—C(═O)—*′, and*—C(═S)—*′,

*₁, *₂, *₃, and *₄ may each be a binding site to M,

R₁ to R₈ may each independently be selected from hydrogen, deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamino group, an amidino group, a hydrazino group, a hydrazono group, acarboxylic acid group or a salt thereof, a sulfonic acid group or a saltthereof, a phosphoric acid group or a salt thereof, a substituted orunsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, asubstituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,—C(Q₁)(Q₂)(Q₃), —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂),—C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁), —P(═O)(Q₁)(Q₂), and —P(═S)(Q₁)(Q₂),wherein adjacent groups from among R₁ to R₈ may optionally be bound toform a substituted or unsubstituted C₅-C₆₀ carbocyclic group (or asubstituted or unsubstituted C₄-C₃₀ carbocyclic group) or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group,

adjacent groups from among R₁ to R₈ and Y₁ to Y₄ may optionally be boundto form a substituted or unsubstituted C₅-C₆₀ carbocyclic group (or asubstituted or unsubstituted C₄-C₃₀ carbocyclic group) or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group,

b1 to b4 may each independently be an integer from 0 to 10, and

at least one substituent of the substituted C₆-C₃₀ arylene group, thesubstituted C₁-C₃₀ heteroarylene group, the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₁-C₆₀ heteroaryl group, the substituted monovalentnon-aromatic condensed polycyclic group, the substituted monovalentnon-aromatic condensed heteropolycyclic group, the substituted C₅-C₆₀carbocyclic group (or the substituted C₄-C₃₀ carbocyclic group), and thesubstituted C₁-C₆₀ heterocyclic group may be selected from theaforementioned substituents.

In some embodiments, M in Formula 1 may be selected from iridium (Ir),platinum (Pt), osmium (Os), ruthenium (Ru), rhodium (Rh), palladium(Pd), copper (Cu), silver (Ag), gold (Au), titanium (Ti), zirconium(Zr), hafnium (Hf), europium (Eu), terbium (Tb), and thulium (Tm), butthe present disclosure is not limited thereto.

In some embodiments, the fourth compound may be a compound where M is Iror Pt, but the present disclosure is not limited thereto.

According to one or more embodiments, in Formulae 1A to 1C, CY₁ to CY₄may each independently be selected from a benzene group, a naphthalenegroup, an anthracene group, a phenanthrene group, a triphenylene group,a pyrene group, a chrysene group, a cyclopentadiene group, a1,2,3,4-tetrahydronaphthalene group, a carbene moiety-containing group,a thiophene group, a furan group, a selenophene group, an indole group,a benzoborole group, a benzophosphole group, an indene group, abenzosilole group, a benzogermole group, a benzothiophene group, abenzoselenophene group, a benzofuran group, a carbazole group, adibenzoborole group, a dibenzophosphole group, a fluorene group, adibenzosilole group, a dibenzogermole group, a dibenzothiophene group, adibenzoselenophene group, a dibenzofuran group, a dibenzothiophene5-oxide group, a 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxidegroup, an azaindole group, an azabenzoborole group, an azabenzophospholegroup, an azaindene group, an azabenzosilole group, an azabenzogermolegroup, an azabenzothiophene group, an azabenzoselenophene group, anazabenzofuran group, an azacarbazole group, an azadibenzoborole group,an azadibenzophosphole group, an azafluorene group, an azadibenzosilolegroup, an azadibenzogermole group, an azadibenzothiophene group, anazadibenzoselenophene group, an azadibenzofuran group, anazadibenzothiophene 5-oxide group, an aza-9H-fluoren-9-one group, anazadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidinegroup, a pyrazine group, a pyridazine group, a triazine group, aquinoline group, an isoquinoline group, a quinoxaline group, aquinazoline group, a phenanthroline group, a pyrrole group, a pyrazolegroup, an imidazole group, a triazole group, an oxazole group, anisooxazole group, a thiazole group, an isothiazole group, an oxadiazolegroup, a thiadiazole group, a benzopyrazole group, a benzimidazolegroup, a benzoxazole group, a benzothiazole group, a benzoxadiazolegroup, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group,and a 5,6,7,8-tetrahydroquinoline group.

According to one or more embodiments, at least one selected from CY₁ andCY₂ in Formula 1A, at least one selected from CY₁ to CY₃ in Formula 1B,and at least one selected from CY₁ to CY₄ in Formula 1C may be a carbenemoiety-containing group.

According to one or more embodiments, in Formulae 1A to 1C, Y₁ to Y₄ mayeach independently be selected from a single bond, a double bond,*—O—*′, *—S—*′, *—C(R₅)(R₆)—*′, and *—N(R₅)—*′.

In some embodiments, in Formulae 1A to 1C, R₁ to R₈ may eachindependently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a cyano group, aphenyl group, and a biphenyl group;

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a spiro-fluorene-benzofluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a pyrenyl group, aphenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, a silolyl group, an imidazolyl group,a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, apyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolylgroup, an indazolyl group, a purinyl group, a quinolinyl group, anisoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, a benzosilolyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, adibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinylgroup, an imidazopyrimidinyl group, an oxazolopyridinyl group, athiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenylgroup, an azaspiro-bifluorenyl group, an azacarbazolyl group, anazadibenzofuranyl group, an azadibenzothiophenyl group, anazadibenzosilolyl group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), and —B(Q₁)(Q₂);and

a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a spiro-fluorene-benzofluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a pyrenyl group, aphenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, a silolyl group, an imidazolyl group,a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, apyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolylgroup, an indazolyl group, a purinyl group, a quinolinyl group, anisoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, a benzosilolyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, adibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinylgroup, an imidazopyrimidinyl group, an oxazolopyridinyl group, athiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenylgroup, an azaspiro-bifluorenyl group, an azacarbazolyl group, anazadibenzofuranyl group, an azadibenzothiophenyl group, and anazadibenzosilolyl group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, acyclohexyl group, a cycloheptyl group, a cyclopentenyl group, acyclohexenyl group, a phenyl group, a naphthyl group, a fluorenyl group,a spiro-bifluorenyl group, a spiro-fluorene-benzofluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a pyrenyl group, aphenalenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrrolyl group, athiophenyl group, a furanyl group, a silolyl group, an imidazolyl group,a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, apyrimidinyl group, a pyridazinyl group, an indolyl group, an isoindolylgroup, an indazolyl group, a purinyl group, a quinolinyl group, anisoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, anaphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, acinnolinyl group, a phenanthridinyl group, an acridinyl group, aphenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, abenzofuranyl group, a benzothiophenyl group, a benzosilolyl group, anisobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group,a triazolyl group, a tetrazolyl group, an oxadiazolyl group, a triazinylgroup, a dibenzofuranyl group, a dibenzothiophenyl group, adibenzosilolyl group, a carbazolyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a thiadiazolyl group, an imidazopyridinylgroup, an imidazopyrimidinyl group, an oxazolopyridinyl group, athiazolopyridinyl group, a benzonaphthyridinyl group, an azafluorenylgroup, an azaspiro-bifluorenyl group, an azacarbazolyl group, anazadibenzofuranyl group, an azadibenzothiophenyl group, anazadibenzosilolyl group, a biphenyl group, and a terphenyl group,

wherein Q₁ to Q₃ may each independently be selected from hydrogen,deuterium, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group,a naphthyl group, a fluorenyl group, a carbazolyl group, adibenzofuranyl group, a dibenzothiophenyl group, a triphenylenyl group,a biphenyl group, a terphenyl group, and a tetraphenyl group.

According to one or more embodiments, at least one selected from R₁ toR₂ in Formula 1A, at least one selected from R₁ to R₃ in Formula 1B, andat least one selected from R₁ to R₄ in Formula 1C may each be anelectron-donating group.

In some embodiments, the electron-donating group may be a substituentselected from an iso-propyl group, a tert-butyl group, and groupsrepresented by Formulae 10-1 to 10-61:

wherein, in Formulae 10-1 to 10-61,

“i-Pr” represents an iso-propyl group, “t-Bu” represents a t-butylgroup,

“Ph” represents a phenyl group, and

* indicates a binding site to an adjacent atom.

In some embodiments, i) at least one selected from R₁ to R₂ in Formula1A may be a substituent other than hydrogen, and/or Y₁ may be*—N(R₅)—*′, and R₅ may be a substituted C₆-C₆₀ aryl group, ii) at leastone selected from R₁ to R₃ in Formula 1B may be a substituent other thanhydrogen, and/or at least one selected from Y₁ and Y₂ may be *—N(R₅)—*′,and R₅ may be a substituted C₆-C₆₀ aryl group, and iii) at least oneselected from R₁ to R₄ in Formula 1C may be a substituent other thanhydrogen, and/or at least one selected from Y₁ to Y₄ may be *—N(R₅)—*′,and R₅ may be a substituted C₆-C₆₀ aryl group.

According to one or more embodiments, the third compound and the fourthcompound may each independently be selected from compounds representedby Formulae 1-1 and 1-2:

wherein, in Formulae 1-1 and 1-2,

M, L₂, n1, n2, CY₁ to CY₄, Y₁ to Y₃, a1 to a3, T₁ to T₄, R₁ to R₄, andb1 to b4 may respectively be understood by referring to the descriptionsof M, L₂, n1, n2, CY₁ to CY₄, Y₁ to Y₃, a1 to a3, T₁ to T₄, R₁ to R₄,and b1 to b4 provided herein.

According to one or more embodiments, at least one selected from CY₁ andCY₂ in Formula 1-1 and at least one selected from CY₁ to CY₄ in Formula1-2 may each be a carbene moiety-containing group.

In some embodiments, at least one selected from CY₁ and CY₄ in Formula1-2 may be a carbene moiety-containing group.

In some embodiments, the third compound may be a compound represented byFormula 2-1, and the fourth compound may be a compound represented byFormula 2-2:

wherein, in Formulae 2-1 and 2-2,

M₁ may be Pt,

M₂ may be selected from a first-row transition metal, a second-rowtransition metal, and a third-row transition metal,

CY₁₂ to CY₁₄ and CY₂₂ to CY₂₄ may each independently be selected from aC₅-C₃₀ carbocyclic group (or a C₄-C₃₀ carbocyclic group) and a C₁-C₃₀heterocyclic group,

A₁₁, A₁₂, A₂₁, and A₂₂ may each independently be N or P,

X₁₁ to X₁₃ and X₂₁ to X₂₃ may each independently be N or C,

Y₁₁ to Y₁₃ may each independently be selected from a single bond, adouble bond, a substituted or unsubstituted C₆-C₃₀ arylene group, asubstituted or unsubstituted C₁-C₃₀ heteroarylene group, *—O—*′, *—S—*′,*—C(═O)—*′, *—S(═O)—*′, *—C(R₁₅)(R₁₆)—*′, *—C(R₁₅)═C(R₁₆)—*′,*—C(R₁₅)═*′, *—Si(R₁₅)(R₁₆)—*′, *—B(R₁₅)—*′, *—N(R₁₅)—*′, and*—P(R₁₅)—*′,

Y₂₁ to Y₂₃ may each independently be selected from a single bond, adouble bond, a substituted or unsubstituted C₆-C₃₀ arylene group, asubstituted or unsubstituted C₁-C₃₀ heteroarylene group, *—O—*′, *—S—*′,*—C(═O)—*′, *—S(═O)—*′, *—C(R₂₅)(R₂₆)—*′, *—C(R₂₅)═C(R₂₆)—*′,*—C(R₂₅)═*′, *—Si(R₂₅)(R₂₆)—*′, *—B(R₂₅)—*′, *—N(R₂₅)—*′, and*—P(R₂₅)—*′,

a11 to a13 may each independently be selected from 1, 2, and 3,

a21 to a23 may each independently be selected from 1, 2, and 3,

T₁₁ to T₁₄ may each independently be selected from a chemical bond(e.g., a single bond), *—O—*′, *—S—*′, *—B(R₁₇)—*′, *—N(R₁₇)—*′,*—P(R₁₇)—*′, *—C(R₁₇)(R₁₈)—*′, *—Si(R₁₇)(R₁₈)—*′, *—Ge(R₁₇)(R₁₈)—*′,*—C(═O)—*′, and *—C(═S)—*′,

T₂₁ to T₂₄ may each independently be selected from a chemical bond(e.g., a single bond), *—O—*′, *—S—*′, *—B(R₂₇)—*′, *—N(R₂₇)—*′,*—P(R₂₇)—*′, *—C(R₂₇)(R₂₈)—*′, *—Si(R₂₇)(R₂₈)—*′, *—Ge(R₂₇)(R₂₈)—*′,*—C(═O)—*′, and *—C(═S)—*′,

R_(11a) to R_(11c), R₁₂ to R₁₈, R_(21a) to R_(21c), and R₂₂ to R₂₈ mayeach independently be selected from hydrogen, deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazino group, a hydrazono group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —C(Q₁)(Q₂)(Q₃), —Si(Q₁)(Q₂)(Q₃),—B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁),—P(═O)(Q₁)(Q₂), and —P(═S)(Q₁)(Q₂), wherein adjacent groups from amongR_(11a) to R_(11c) and R₁₂ to R₁₈ may optionally be bound to form asubstituted or unsubstituted C₅-C₆₀ carbocyclic group (or a substitutedor unsubstituted C₄-C₃₀ carbocyclic group) or a substituted orunsubstituted C₁-C₆₀ heterocyclic group, and adjacent groups from amongR_(21a) to R_(21c) and R₂₂ to R₂₈ may optionally be bound from asubstituted or unsubstituted C₅-C₆₀ carbocyclic group (or a substitutedor unsubstituted C₄-C₃₀ carbocyclic group) or a substituted orunsubstituted C₁-C₆ heterocyclic group, and

b12 to b14 and b22 to b24 may each independently be an integer from 0 to10.

According to one or more embodiments, R_(11b) and R_(11c) in Formula 2-1and/or R_(21b) and R_(21c) in Formula 2-2 may be bound to each other toform a benzene ring, a naphthalene ring, a pyridine ring, a pyrimidinering, and a pyrazine ring, each unsubstituted or substituted with atleast one Ra, and Ra may be understood by referring to the descriptionof R_(11a) provided herein.

According to one or more embodiments, at least one selected from R_(11a)to R_(11c) and R₁₄ in Formula 2-1 may be an electron-donating group.

In some embodiments, at least one selected from R_(11a) and R₁₄ inFormula 2-1 may be an electron-donating group. According to one or moreembodiments, at least one selected from R_(11a) and R₁₄ in Formula 2-1may be an electron-donating group selected from an iso-propyl group, atert-butyl group, and groups represented by Formulae 10-1 to 10-61:

wherein, in Formulae 10-1 to 10-61,

“i-Pr” represents an iso-propyl group, “t-Bu” represents a t-butylgroup,

“Ph” represents a phenyl group, and

* indicates a binding site to an adjacent atom.

According to one or more embodiments, at least one selected from R₂₂ andR₂₃ in Formula 2-2 may be a substituent other than hydrogen, and/or Y₂₃may be *—N(R₂₅)—*′, and R₂₅ may be a substituted C₆-C₆₀ aryl group.

In some embodiments, at least one selected from R₂₂ and R₂₃ may beselected from a substituted or unsubstituted C₁-C₆₀ alkyl group, asubstituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted orunsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstitutedC₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkylgroup, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, and asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, and/or Y₂₃ may be *—N(R₂₅)—*′, and R₂₅ may be asubstituted C₆-C₆₀ aryl group.

In some embodiments, at least one selected from R₂₂ and R₂₃ may be aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, aC₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group, each substituted with at least onedeuterium, and/or Y₂₃ may be *—N(R₂₅)—*′, and R₂₅ may be a C₆-C₆₀ arylgroup substituted with at least one deuterium.

In some embodiments, at least one selected from R₂₂ and R₂₃ may beselected from an iso-propyl group, a tert-butyl group, and anelectron-donating group selected from groups represented by Formulae10-1 to 10-61, and/or Y₂₃ may be *—N(R₁₅)—*′, and R₂₅ may be aniso-propyl group, a tert-butyl group, and an electron-donating groupselected from groups represented by Formulae 10-1 to 10-61.

In some embodiments, at least one selected from R_(11a) to R_(11c) andR₁₄ in Formula 2-1 may be an electron-donating group, and at least oneselected from R₂₂ and R₂₃ in Formula 2-2 may be a substituent other thanhydrogen, and/or Y₂₃ may be *—N(R₂₅)—*′, and R₂₅ may be a substitutedC₆-C₆₀ aryl group.

In some embodiments, the third compound may be a compound represented byFormula 2-1A or Formula 2-1B:

wherein, in Formulae 2-1A and 2-1B,

Z₁₁ may be C(R_(12a)) or N, Z₁₂ may be C(R_(12b)) or N, Z₁₃ may beC(R_(12c)) or N, Z₁₄ may be C(R_(13a)) or N, Z₁₅ may be C(R_(13b)) or N,Z₁₆ may be C(R_(13c)) or N, Z₁₇ may be C(R_(14a)) or N, Z₁₈ may beC(R_(14b)) or N, Z₁₉ may be C(R_(14c)) or N, and Z₂₀ may be C(R_(14d))or N,

Z₃₁ may be C(R_(15a)) or N, Z₃₂ may be C(R_(15b)) or N, Z₃₃ may beC(R_(15c)) or N, and Z₃₄ may be C(R_(15d)) or N,

R_(12a) to R_(12c) may each be understood by referring to thedescription of R₁₂ provided herein,

R_(13a) to R_(13c) may each be understood by referring to thedescription of R₁₃ provided herein,

R_(14a) to R_(14d) may each be understood by referring to thedescription of R₁₄ provided herein,

R_(15a) to R_(15d) may each be understood by referring to thedescription of R₁₅ provided herein, and

M₁, CY₁₂ to CY₁₄, A₁₁, A₁₂, X₁₁ to X₁₃, Y₁₁ to Y₁₃, a11 to a13, T₁₁ toT₁₄, and R_(11a) to R_(11c) may respectively be understood by referringto the descriptions of M₁, CY₁₂ to CY₁₄, A₁₁, A₁₂, X₁₁ to X₁₃, Y₁₁ toY₁₃, a11 to a13, T₁₁ to T₁₄, and R_(11a) to R_(11c) provided herein.

According to one or more embodiments, in Formulae 2-1A and 2-1B, Z₁₈ maybe C(R_(14b)), and at least one selected from R_(11a) to R_(11c) andR_(14b) may be an electron-donating group. In some embodiments, inFormulae 2-1A and 2-1B, Z₁₈ may be C(R_(14b)), and at least one selectedfrom R_(11a) and R_(14b) may be an electron-donating group.

According to one or more embodiments, in Formulae 2-1A and 2-1B, Z₁₈ maybe C(R_(14b)), and at least one selected from R_(11a) and R_(14b) may bean electron-donating group selected from an iso-propyl group, atert-butyl group, and groups represented by Formulae 10-1 to 10-61.

According to one or more embodiments, the fourth compound may be acompound represented by Formula 2-2A:

wherein in Formula 2-2A,

Z₂₁ may be C(R_(22a)) or N, Z₂₂ may be C(R_(22b)) or N, Z₂₃ may beC(R_(22c)) or N, Z₂₄ may be C(R_(23a)) or N, Z₂₅ may be C(R_(23b)) or N,Z₂₇ may be C(R_(24a)) or N, Z₂₈ may be C(R_(24b)) or N, Z₂₉ may beC(R_(24c)) or N, Z₃₀ may be C(R_(24d)) or N, Z₄₁ may be C(R_(25a)) or N,Z₄₂ may be C(R_(25b)) or N, Z₄₃ may be C(R₂₅ c) or N, and Z₄₄ may beC(R_(25d)) or N,

R_(22a) to R_(22c) may each be understood by referring to thedescription of R₂₂ provided herein,

R_(23a) to R_(23c) may each be understood by referring to thedescription of R₂₃ provided herein,

R_(24a) to R_(24d) may each be understood by referring to thedescription of R₂₄ provided herein,

R_(25a) to R_(25d) may each be understood by referring to thedescription of R₂₅ provided herein, and

M₂, CY₂₂ to CY₂₄, A₂₁, A₂₂, X₂₁ to X₂₃, Y₂₁ to Y₂₃, a21 to a23, T₂₁ toT₂₄, and R_(21a) to R_(21c) may respectively be understood by referringto the descriptions of M₂, CY₂₂ to CY₂₄, A₂₁, A₂₂, X₂₁ to X₂₃, Y₂₁ toY₂₃, a21 to a23, T₂₁ to T₂₄, and R_(21a) to R_(21c) provided herein.

According to one or more embodiments, in Formula 2-2A, M₂ may be Pt.

According to one or more embodiments, in Formula 2-2A, Z₂₂ may beC(R_(22b)), Z₄₂ may be C(R_(25b)), and at least one selected fromR_(22b) and R_(25b) may be a substituent other than hydrogen. In someembodiments, at least one selected from R_(22b) and R_(25b) may be asubstituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, and asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group.

In some embodiments, in Formula 2-2A, Z₂₂ may be C(R_(22b)), Z₄₂ may beC(R_(25b)), and at least one selected from R_(22b) and R_(25b) may be aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, aC₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group, each substituted with at least onedeuterium.

In some embodiments, in Formula 2-2A, Z₂₂ may be C(R_(22b)), Z₄₂ may beC(R_(25b)), and at least one selected from R_(22b) and R_(25b) may be anelectron-donating group selected from an iso-propyl group, a tert-butylgroup, and groups represented by Formulae 10-1 to 10-61.

According to one or more embodiments, the third compound may be selectedfrom Compounds BD1, BD2, and Pt-1 to Pt-24, but the present disclosureis not limited thereto:

According to one or more embodiments, the fourth compound may beselected from the following compounds, but the present disclosure is notlimited thereto:

According to one or more embodiments, a weight ration of the thirdcompound to the fourth compound may be in a range of about 100:1 toabout 1:100, but the present disclosure is not limited thereto.

In some embodiments, a difference between a maximum emission wavelengthof light emitted from the third compound and a maximum emissionwavelength of light emitted from the fourth compound may be in a rangeof about 0 nanometer (nm) to about 35 nm, for example, about 0 nm toabout 20 nm, or for example, about 0 nm to about 10 nm.

According to one or more embodiments, the third compound and the fourthcompound may each emit blue light. In some embodiments, the thirdcompound may emit light having a maximum emission wavelength in a rangeof about 445 nm to about 470 nm, and the fourth compound may emit lighthaving a maximum emission wavelength in a range of about 450 nm to about480 nm. In some embodiments, a difference between a maximum emissionwavelength of light emitted from the third compound and a maximumemission wavelength of light emitted from the fourth compound may be ina range of about 0 nm to about 35 nm.

As the organic light-emitting device includes the third compound as adopant, the color purity of blue light emitted from the emission layermay improve.

In some embodiments, a y coordinate among CIE color-coordinates of lightemitted from the emission layer may be in a range of about 0.045 toabout 0.06. Accordingly, the organic light-emitting device may emit bluelight with high color purity.

The term “CIE color-coordinates,” as used herein, refers to x, y, zcoordinates of light according to CIE 1931 color space.

When the fourth compound is included as a co-dopant with the thirdcompound in the emission layer, the organic light-emitting device mayhave long lifespan. In some embodiments, when driven by the sameluminance under the same condition of thickness and composition oforganic layers, an organic light-emitting device including the fourthcompound as an emission layer dopant (hereinafter, referred to as a“first device”) may have a longer T95 lifespan than an organiclight-emitting device including the third compound (or only the thirdcompound) as an emission layer dopant (hereinafter, referred to as a“second device”).

Accordingly, according to one or more embodiments, the organiclight-emitting device 10 may satisfy Equation 1:

T95(C4)>T95(C3)  Equation 1

wherein, in Equation 1,

T95(C3) indicates a T95 lifespan of the organic light-emitting deviceincluding the third compound as a single dopant in the emission layer(the second device), and

T95(C4) indicates a T95 lifespan of the organic light-emitting deviceincluding the fourth compound as a single dopant in the emission layer(the first device).

In Equation 1, T95(C4) and T95(C3) may each be a T95 lifespan whendriven by the same initial luminance.

A content ratio (e.g., weight ratio or mole ratio) of the third compoundto the fourth compound in the emission layer may differ depending on thelifespan ratio of the second device to the first device.

In some embodiments, when the T95 lifespan of the second device issmaller than the T95 lifespan of the first device and greater than orequal to 80% of the T95 lifespan of the first device, the content ratio(e.g., weight ratio or mole ratio) of the third compound to the fourthcompound may be in a range of about 1:0.01 to about 1:1, or for example,about 1:0.1 to about 1:0.5.

In some embodiments, when the T95 lifespan of the second device issmaller than 80% of the T95 lifespan of the first device and greaterthan or equal to 50% of the T95 lifespan of the first device, thecontent ratio (e.g., weight ratio or mole ratio) of the third compoundto the fourth compound may be in a range of about 1:0.01 to about0.01:1, for example, about 1:0.5 to about 1:0.8, or for example, about0.5:1 to about 0.8:1.

In some embodiments, when the T95 lifespan of the second device issmaller than 50% of the T95 lifespan of the first device, a weight ratioof the third compound to the fourth compound may be in a range of about1:0.01 to about 0.01:1, or for example, about 0.3:1 to about 0.5:1.

The organic light-emitting device according to one or more embodimentsincludes both the third compound and the fourth compound as emissionlayer dopants, thus having color purity improvement by the thirdcompound and lifespan improvement by the fourth compound.

According to one or more embodiments, the organic light-emitting devicemay have a T95 lifespan of 30 hours or longer, based on the initialluminance of 1,000 nit.

According to one or more embodiments, the total content (e.g., amount orvolume) of the third compound and the fourth compound in the emissionlayer may be generally in a range of about 1 percent by volume (vol %)to about 50 vol %, for example, about 5 vol % to about 50 vol %, or forexample, about 10 vol % to about 25 vol %, based on the total volume ofthe first compound and the second compound, but the present disclosureis not limited thereto.

According to one or more embodiments, the emission layer may include atleast one selected from a fluorescent dopant and delayed fluorescentdopant.

According to one or more embodiments, the fluorescent dopant may includea compound represented by Formula 501:

wherein, in Formula 501,

Ar₅₀₁ may be selected from a substituted or unsubstituted C₅-C₆₀carbocyclic group (or a substituted or unsubstituted C₄-C₆₀ carbocyclicgroup) and a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

L₅₀₁ to L₅₀₃ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xd1 to xd3 may each independently be an integer from 0 to 3,

R₅₀₁ and R₅₀₂ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group,and

xd4 may be an integer from 1 to 6.

In some embodiments, in Formula 501, Ar₅₀₁ may be selected from:

a naphthalene group, a heptalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, and an indenophenanthrenegroup; and

a naphthalene group, a heptalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, and an indenophenanthrenegroup, each substituted with at least one selected from deuterium, —F,—Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidinogroup, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, aC₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, and a naphthyl group.

In an embodiment, in Formula 501, L₅₀₁ and L₅₀₃ may each independentlybe selected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, and a pyridinylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, and a pyridinylene group, each substituted withat least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group.

In an embodiment, in Formula 501, R₅₀₁ and R₅₀₂ may each independentlybe selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, and a pyridinyl group, each substituted with atleast one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenylgroup, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃),

wherein Q₃₁ to Q₃₃ may be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and anaphthyl group.

In one or more embodiments, xd4 in Formula 501 may be 2, but the presentdisclosure is not limited thereto.

In some embodiments, the fluorescent dopant may be selected fromCompounds FD1 to FD22:

In some embodiments, the fluorescent dopant may be selected from thefollowing compounds, but the present disclosure is not limited thereto:

The delayed fluorescent dopant may satisfy Equation 3:

ΔE _(ST) =|S1(D)−T1(D)|≤0.5 eV  Equation 3

wherein, in Equation 3,

S1(D) indicates a lowest excited singlet energy level of the dopant, and

T1(D) indicates a lowest excited triplet energy level of the dopant.

A delayed fluorescent dopant that satisfy Equation 3 may emit thermalactivated delayed fluorescence (TADF) even at room temperature. In someembodiments, the delayed fluorescent dopant may satisfy|S1(D)−T1(D)|≤0.2 eV, but the present disclosure is not limited thereto.

In addition, the delayed fluorescent dopant may not include a metalatom. For example, the delayed fluorescent dopant is distinguished froma phosphorescent dopant including a metal atom. In some embodiments, thedelayed fluorescent dopant may not include iridium (Ir), platinum (Pt),palladium (Pd), osmium (Os), titanium (Ti), zirconium (Zr), hafnium(Hf), europium (Eu), terbium (Tb), rhodium (Rh), and thulium (Tm) and bedistinguished from the phosphorescent dopant.

In some embodiments, the emission layer may include a first emissionlayer and a second emission layer, and the first emission layer may bebetween the first electrode and the second emission layer. In thisembodiment, the first emission layer may include the first compound, thesecond compound, and a first dopant, and the second emission layer mayinclude the first compound, the second compound, and a second dopant,wherein the first dopant may be any one selected from the third compoundand the fourth compound, the second dopant may be different from thefirst dopant and may be the other one of the third compound and thefourth compound.

As described above, the third compound and the fourth compound may eachbe included in different emission layers.

In some embodiments, the third compound may be included in a firstemission layer, and the fourth compound may be included in a secondemission layer, or the fourth compound may be included in a firstemission layer, and the third compound may be included in a secondemission layer.

The first emission layer and the second emission layer may be in directcontact (e.g., physical contact) with each other, or another organiclayer may be between the first emission layer and the second emissionlayer.

According to one or more embodiments, the first emission layer and thesecond emission layer may be in direct contact (e.g., physical contact)with each other.

According to one or more embodiments, the organic light-emitting devicemay further include a charge-generation layer between the first emissionlayer and the second emission layer and including an n-typecharge-generation layer and a p-type charge-generation layer.

One emission layer of the first emission layer and the second emissionlayer may be physically in contact with the charge-generation layer, andanother layer may be between the one emission layer and thecharge-generation layer. In some embodiments, an electron transportregion may be between a first emission layer, from among the twoemission layers, and the charge-generation layer, the first emissionlayer being adjacent to a first electrode. In some embodiments, a holetransport region may be between a second emission layer, from among thetwo emission layers, and a charge-generation layer, the second emissionlayer being adjacent to a second electrode.

The charge-generation layer may generate charge or separate holes andelectrons to serve as a cathode for an emission unit of two adjacentemission units by injecting electrons and as an anode for the otheremission unit by injecting holes. The charge-generation layer may serveto separate adjacent emission units while not being directly coupled toan electrode.

The term “n-type,” as used herein, refers to n-type semiconductorproperties, e.g., properties capable of injection and transport ofelectrons. The term “p-type,” as used herein, refers to p-typesemiconductor properties, e.g., properties capable of injection andtransport of holes.

According to one or more embodiments, the first dopant may be includedin a range of about 1 vol % to about 30 vol %, based on the total volumeof the first emission layer, and the second dopant may be included in arange of about 1 vol % to about 30 vol %, based on the total volume ofthe second emission layer, but the present disclosure is not limitedthereto.

The thicknesses of the first emission layer and the second emissionlayer may each be in a range of about 10 Å to about 1,000 Å, and in someembodiments, about 150 Å to about 500 Å. When the thicknesses of thefirst emission layer and the second emission layer are within any of theforegoing ranges, luminescence characteristics may be improved without asubstantial increase in driving voltage.

According to one or more embodiments, a thickness ratio of the firstemission layer to the second emission layer may be in a range of about1:9 to about 9:1. In some embodiments, the thickness ratio may be in arange of about 2:8 to about 8:2, or for example, about 7:3 to about 3:7.

In some embodiments, a difference between a maximum emission wavelengthof light emitted from the first emission layer and a maximum emissionwavelength of light emitted from the second emission layer may be in arange of about 0 nm to about 35 nm, for example, about 0 nm to about 20nm, or for example, about 0 nm to about 10 nm.

According to one or more embodiments, the first emission layer and thesecond emission layer may each emit blue light. In this embodiment, adifference between a maximum emission wavelength of light emitted fromthe first emission layer and a maximum emission wavelength of lightemitted from the second emission layer may be in a range of about 0 nmto about 35 nm, for example, about 0 nm to about 20 nm, or for example,about 0 nm to about 10 nm.

In some embodiments, the emission layer may include a first emissionlayer, a second emission layer and a third emission layer, and the firstemission layer may be between the first electrode and the secondemission layer, and the second emission layer may be between the firstelectrode and the third emission layer. In this embodiment, the firstemission layer may include the first compound, the second compound, anda first dopant, the second emission layer may include the firstcompound, the second compound, and a second dopant, and the thirdemission layer may include the first compound, the second compound, anda third dopant, wherein the first dopant and the third dopant may be anyone selected from the third compound and the fourth compound, the seconddopant may be different from the first dopant and the third dopant andbe the other one of the third compound and the fourth compound.

As described above, the third compound and the fourth compound may eachbe included in different emission layers. In some embodiments, the thirdcompound may be included in a first emission layer and a third emissionlayer, and the fourth compound may be included in a second emissionlayer, or the fourth compound may be included in a first emission layerand a third emission layer, and the third compound may be included in asecond emission layer.

When the first emission layer and the third emission layer includes thethird compound, the third compound included in the first emission layermay be identical to or different from the third compound included in thethird emission layer. For example, the first dopant and the third dopantmay each independently be an organometallic compound represented byFormula 1, and the first dopant and the third dopant may be identical toor different from each other.

When the first emission layer and the third emission layer includes thefourth compound, the fourth compound included in the first emissionlayer may be identical to or different from the fourth compound includedin the third emission layer.

The first emission layer, the second emission layer, and the thirdemission layer may be in direct contact (e.g., physical contact) witheach other, or another organic layer may be between the first emissionlayer and the second emission layer and/or the second emission layer andthe third emission layer.

According to one or more embodiments, the first emission layer, thesecond emission layer, and the third emission layer may be in directcontact (e.g., physical contact) with one another. For example, thesecond emission layer may be at an interface between the first emissionlayer and the third emission layer.

According to one or more embodiments, the organic light-emitting devicemay further include a charge-generation layer between two adjacentemission layers from among the first emission layer, the second emissionlayer, and the third emission layer and including an n-typecharge-generation layer and a p-type charge-generation layer. The term“adjacent,” as used herein, refers to an arrangement relationship oflayers arranged to be closest to each other from among the describedlayers. In some embodiments, the term “two adjacent emission layers,” asused herein, refers to an arrangement relationship of two emissionlayers arranged to be closest to each other from among a plurality ofemission layers.

One emission layer of the two emission layers closest to each other maybe physically in contact with the charge-generation layer, and anotherlayer may be between the one emission layer and the charge-generationlayer. In some embodiments, an electron transport region may be betweenan emission layer, from among the two adjacent emission layers, adjacentto a first electrode and the charge-generation layer. In someembodiments, a hole transport region may be between an emission layer,from among the two adjacent emission layers, adjacent to a secondelectrode and a charge-generation layer.

According to one or more embodiments, the first dopant may be includedin a range of about 1 vol % to about 30 vol %, based on the total volumeof the first emission layer, the second dopant may be included in arange of about 1 vol % to about 30 vol %, based on the total volume ofthe second emission layer, and the third dopant may be included in arange of about 1 vol % to about 30 vol %, based on the total volume ofthe third emission layer, but the present disclosure is not limitedthereto.

The thicknesses of the first emission layer, the second emission layer,and the third emission layer may each independently be in a range ofabout 10 Å to about 1,000 Å, and in some embodiments, about 150 Å toabout 500 Å. When the thicknesses of the first emission layer, thesecond emission layer, and the third emission layer are within any ofthe foregoing ranges, luminescence characteristics may be improvedwithout a substantial increase in driving voltage.

According to one or more embodiments, the first emission layer, thesecond emission layer, and the third emission layer may each emit bluelight. In this embodiment, a difference between a maximum emissionwavelength of light emitted from the first emission layer, a maximumemission wavelength of light emitted from the second emission layer, anda maximum emission wavelength of light emitted from the third emissionlayer may be in a range of about 0 nm to about 35 nm, for example, about0 nm to about 20 nm, or for example, about 0 nm to about 10 nm.

When the organic light-emitting device 10 is a full color organiclight-emitting device, the emission layer may be patterned into a redemission layer, a green emission layer, or a blue emission layer,according to a sub-pixel. In one or more embodiments, the emission layermay have a stacked structure. The stacked structure may include two ormore layers selected from a red emission layer, a green emission layer,and a blue emission layer. The two or more layers may be in directcontact (e.g., physical contact) with each other. In some embodiments,the two or more layers may be separated from each other. In one or moreembodiments, the emission layer may include two or more materials. Thetwo or more materials may include a red light-emitting material, a greenlight-emitting material, or a blue light-emitting material. The two ormore materials may be mixed with each other in a single layer. The twoor more materials mixed with each other in the single layer may emitwhite light.

The total thickness of the emission layer may be in a range of about 20Å to about 1,000 Å, for example, about 200 Å to about 600 Å, or forexample, about 150 Å to about 500 Å. When the thickness of the emissionlayer is within any of the foregoing ranges, improved luminescencecharacteristics may be obtained without a substantial increase indriving voltage.

The organic layer 150 may further include a hole transport regionbetween the first electrode 110 and the emission layer and an electrontransport region between the emission layer and the second electrode190.

Hole Transport Region in Organic Layer 150

The hole transport region may have i) a single-layered structureincluding (or consisting of) a single layer including (or consisting of)a single material, ii) a single-layered structure including (orconsisting of) a single layer including a plurality of differentmaterials, or iii) a multi-layered structure having a plurality oflayers including a plurality of different materials.

The hole transport region may include at least one layer selected from ahole injection layer, a hole transport layer, an emission auxiliarylayer, and an electron blocking layer.

For example, the hole transport region may have a single-layeredstructure including a single layer including a plurality of differentmaterials or a multi-layered structure, e.g., a hole injectionlayer/hole transport layer structure, a hole injection layer/holetransport layer/emission auxiliary layer structure, a hole injectionlayer/emission auxiliary layer structure, a hole transportlayer/emission auxiliary layer structure, or a hole injection layer/holetransport layer/electron blocking layer structure, wherein layers ofeach structure are sequentially stacked on the first electrode 110 ineach stated order, but the present disclosure is not limited thereto.

The hole transport region may include at least one selected fromm-MTDATA, TDATA, 2-TNATA, NPB (NPD), p-NPB, TPD, a spiro-TPD, aspiro-NPB, methylated-NPB, TAPC, HMTPD,4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA),polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA),poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS),polyaniline/camphor sulfonic acid (PANI/CSA),(polyaniline)/poly(4-styrenesulfonate) (PANI/PSS), a compoundrepresented by Formula 201, and a compound represented by Formula 202:

wherein, in Formulae 201 and 202,

L₂₀₁ to L₂₀₄ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

L₂₀₅ may be selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a substituted orunsubstituted C₁-C₂₀ alkylene group, a substituted or unsubstitutedC₂-C₂₀ alkenylene group, a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xa1 to xa4 may each independently be an integer from 0 to 3,

xa5 may be an integer from 1 to 10, and

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from asubstituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted orunsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, asubstituted or unsubstituted C₆-C₆₀ arylthio group, a substituted orunsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstitutedmonovalent non-aromatic condensed polycyclic group, and a substituted orunsubstituted monovalent non-aromatic condensed heteropolycyclic group.

In some embodiments, in Formula 202, R₂₀₁ and R₂₀₂ may optionally bebound via a single bond, a dimethyl-methylene group, or adiphenyl-methylene group, and R₂₀₃ and R₂₀₄ may optionally be bound viaa single bond, a dimethyl-methylene group, or a diphenyl-methylenegroup.

In some embodiments, in Formulae 201 and 202,

L₂₀₁ to L₂₀₅ may each independently be selected from:

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anindacenylene group, an acenaphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenalenylene group, a phenanthrenylenegroup, an anthracenylene group, a fluoranthenylene group, atriphenylenylene group, a pyrenylene group, a chrysenylene group, anaphthacenylene group, a picenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, arubicenylene group, a coronenylene group, an ovalenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group; and

a phenylene group, a pentalenylene group, an indenylene group, anaphthylene group, an azulenylene group, a heptalenylene group, anindacenylene group, an acenaphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenalenylene group, a phenanthrenylenegroup, an anthracenylene group, a fluoranthenylene group, atriphenylenylene group, a pyrenylene group, a chrysenylene group, anaphthacenylene group, a picenylene group, a perylenylene group, apentaphenylene group, a hexacenylene group, a pentacenylene group, arubicenylene group, a coronenylene group, an ovalenylene group, athiophenylene group, a furanylene group, a carbazolylene group, anindolylene group, an isoindolylene group, a benzofuranylene group, abenzothiophenylene group, a dibenzofuranylene group, adibenzothiophenylene group, a benzocarbazolylene group, adibenzocarbazolylene group, a dibenzosilolylene group, and apyridinylene group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

In one or more embodiments, xa1 to xa4 may each independently be 0, 1,or 2.

In one or more embodiments, xa5 may be 1, 2, 3, or 4.

In one or more embodiments, R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independentlybe selected from a phenyl group, a biphenyl group, a terphenyl group, apentalenyl group, an indenyl group, a naphthyl group, an azulenyl group,a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group,an indenyl group, a naphthyl group, an azulenyl group, a heptalenylgroup, an indacenyl group, an acenaphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenalenyl group, a phenanthrenyl group, an anthracenyl group,a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, achrysenyl group, a naphthacenyl group, a picenyl group, a perylenylgroup, a pentaphenyl group, a hexacenyl group, a pentacenyl group, arubicenyl group, a coronenyl group, an ovalenyl group, a thiophenylgroup, a furanyl group, a carbazolyl group, an indolyl group, anisoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinylgroup, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may respectively be understood by referring to thedescriptions of Q₃₁ to Q₃₃ provided herein.

In one or more embodiments, in Formula 201, at least one selected fromR₂₀₁ to R₂₀₃ may be selected from:

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group; and

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, adibenzofuranyl group, and a dibenzothiophenyl group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, acyclopentyl group, a cyclohexyl group, a cycloheptyl group, acyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenylgroup, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkylgroup, a phenyl group substituted with —F, a naphthyl group, a fluorenylgroup, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranylgroup, and a dibenzothiophenyl group,

but the present disclosure is not limited thereto.

In one or more embodiments, in Formula 202, i) R₂₀₁ and R₂₀₂ may bebound via a single bond, and/or ii) R₂₀₃ and R₂₀₄ may be bound via asingle bond.

In one or more embodiments, in Formula 202, at least one selected fromR₂₀₁ to R₂₀₄ may be selected from:

a carbazolyl group; and

a carbazolyl group substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, acarbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,

but the present disclosure is not limited thereto.

The compound represented by Formula 201 may be represented by Formula201-1:

In some embodiments, the compound represented by Formula 201 may berepresented by Formula 201-2, but the present disclosure is not limitedthereto:

In some embodiments, the compound represented by Formula 201 may berepresented by Formula 201-2(1), but the present disclosure is notlimited thereto:

The compound represented by Formula 201 may be represented by Formula201A:

In some embodiments, the compound represented by Formula 201 may berepresented by Formula 201A(1), but the present disclosure is notlimited thereto:

In some embodiments, the compound represented by Formula 201 may berepresented by Formula 201A-1, but the present disclosure is not limitedthereto:

The compound represented by Formula 202 may be represented by Formula202-1:

In one or more embodiments, the compound represented by Formula 202 maybe represented by Formula 202-1(1):

In some embodiments, the compound represented by Formula 202 may berepresented by Formula 202A:

In some embodiments, the compound represented by Formula 202 may berepresented by Formula 202A-1:

In Formulae 201-1, 201-2, 201-2(1), 201A, 201A(1), 201A-1, 202-1,202-1(1), 202A, and 202A-1,

L₂₀₁ to L₂₀₃, xa1 to xa3, xa5, and R₂₀₂ to R₂₀₄ may respectively beunderstood by referring to the descriptions of L₂₀₁ to L₂₀₃, xa1 to xa3,xa5, and R₂₀₂ to R₂₀₄ provided herein,

L₂₀₅ may be selected from a phenylene group and a fluorenylene group,

X₂₁₁ may be selected from O, S, and N(R₂₁₁),

X₂₁₂ may be selected from O, S, and N(R₂₁₂),

R₂₁₁ and R₂₁₂ may each be understood by referring to the description ofR₂₀₃ provided herein, and

R₂₁₃ to R₂₁₇ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexylgroup, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group,a phenyl group, a biphenyl group, a terphenyl group, a phenyl groupsubstituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with—F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenylgroup, a heptalenyl group, an indacenyl group, an acenaphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, ananthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group,a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a rubicenyl group, a coronenyl group, an ovalenyl group, athiophenyl group, a furanyl group, a carbazolyl group, an indolyl group,an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, adibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolylgroup, a dibenzocarbazolyl group, a dibenzosilolyl group, and apyridinyl group.

The hole transport region may include at least one compound selectedfrom Compounds HT1 to HT48, but the present disclosure is not limitedthereto:

The thickness of the hole transport region may be in a range of about100 (Angstroms) A to about 10,000 Å, and in some embodiments, about 100Å to about 1,000 Å. When the hole transport region includes at least oneselected from a hole injection layer and a hole transport layer, thethickness of the hole injection layer may be in a range of about 100 Åto about 9,000 Å, and in some embodiments, about 100 Å to about 1,000 Å,and the thickness of the hole transport layer may be in a range of about50 Å to about 3,000 Å, and in some embodiments, about 100 Å to about1,500 Å. When the thicknesses of the hole transport region, the holeinjection layer, and the hole transport layer are within any of theforegoing ranges, excellent hole transport characteristics may beobtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase light emission efficiency bycompensating for an optical resonance distance according to thewavelength of light emitted by an emission layer. The electron blockinglayer may reduce or eliminate the flow of electrons from an electrontransport region. The emission auxiliary layer and the electron blockinglayer may include the aforementioned materials.

p-Dopant

The hole transport region may include a charge generating material aswell as the aforementioned materials, to improve conductive propertiesof the hole transport region. The charge generating material may besubstantially homogeneously or non-homogeneously dispersed in the holetransport region.

The charge generating material may include, for example, a p-dopant.

In some embodiments, the lowest unoccupied molecular orbital (LUMO)energy level of the p-dopant may be −3.5 eV or less.

The p-dopant may include at least one selected from a quinonederivative, a metal oxide, and a cyano group-containing compound, butthe present disclosure is not limited thereto.

In some embodiments, the p-dopant may include:

a quinone derivative, such as tetracyanoquinodimethane (TCNQ) or2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ);

a metal oxide, such as tungsten oxide or molybdenum oxide;

1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (HAT-CN);

F6-TNAP, Compound 201, and Compound 202; and

a compound represented by Formula 221,

but the present disclosure is not limited thereto:

wherein, in Formula 221,

R₂₂₁ to R₂₂₃ may each independently be selected from a substituted orunsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstitutedC₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ arylgroup, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, asubstituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted monovalentnon-aromatic condensed heteropolycyclic group, wherein at least oneselected from R₂₂₁ to R₂₂₃ may include at least one substituent selectedfrom a cyano group, —F, —Cl, —Br, —I, a C₁-C₂₀ alkyl group substitutedwith —F, a C₁-C₂₀ alkyl group substituted with —Cl, a C₁-C₂₀ alkyl groupsubstituted with —Br, and a C₁-C₂₀ alkyl group substituted with —I.

Electron Transport Region in Organic Layer 150

The electron transport region may have i) a single-layered structureincluding (or consisting of) a single layer including (or consisting of)a single material, ii) a single-layered structure including (orconsisting of) a single layer including a plurality of differentmaterials, or iii) a multi-layered structure each having a plurality oflayers, each having a plurality of different materials.

The electron transport region may include at least one selected from abuffer layer, a hole blocking layer, an electron control layer, anelectron transport layer, and an electron injection layer, but thepresent disclosure is not limited thereto.

In some embodiments, the electron transport region may have an electrontransport layer/electron injection layer structure, a hole blockinglayer/electron transport layer/electron injection layer structure, anelectron control layer/electron transport layer/electron injection layerstructure, or a buffer layer/electron transport layer/electron injectionlayer structure, wherein layers of each structure are sequentiallystacked on the emission layer in each stated order, but the presentdisclosure is not limited thereto.

The electron transport region (for example, the buffer layer, the holeblocking layer, the electron control layer, or the electron transportlayer in the electron transport region) may include a metal-freecompound including at least one π electron-depleted nitrogen-containingring.

The term “π electron-depleted nitrogen-containing ring,” as used herein,refers to a C₁-C₆ heterocyclic group having at least one *—N═*′ moietyas a ring-forming moiety.

For example, the “π electron-depleted nitrogen-containing ring” may bei) a 5-membered to 7-membered heteromonocyclic group having at least one*—N═*′ moiety, ii) a heteropolycyclic group in which at least two5-membered to 7-membered heteromonocyclic groups, each having at leastone *—N═*′ moiety, are condensed (e.g., combined together), or iii) aheteropolycyclic group in which at least one selected from a 5-memberedto 7-membered heteromonocyclic group, each having at least one *—N═*′moiety, is condensed with (e.g., combined with) at least one C₅-C₆₀carbocyclic group (or at least one C₄-C₃₀ carbocyclic group).

Examples of the π electron-depleted nitrogen-containing ring may includeimidazole, pyrazole, thiazole, isothiazole, oxazole, isoxazole,pyridine, pyrazine, pyrimidine, pyridazine, indazole, purine, quinoline,isoquinoline, benzoquinoline, phthalazine, naphthyridine, quinoxaline,quinazoline, cinnoline, phenanthridine, acridine, phenanthroline,phenazine, benzimidazole, isobenzothiazole, benzoxazole, isobenzoxazole,triazole, tetrazole, oxadiazole, triazine, thiadiazole, imidazopyridine,imidazopyrimidine, and azacarbazole, but the present disclosure is notlimited thereto.

In some embodiments, the electron transport region may include acompound represented by Formula 601:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21)  Formula 601

wherein, in Formula 601,

Ar₆₀₁ may be selected from a substituted or unsubstituted C₅-C₆₀carbocyclic group and a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup,

xe11 may be 1, 2, or 3,

L₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylenegroup, a substituted or unsubstituted divalent non-aromatic condensedpolycyclic group, and a substituted or unsubstituted divalentnon-aromatic condensed heteropolycyclic group,

xe1 may be an integer from 0 to 5,

R₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁),—S(═O)₂(Q₆₀₁), and —P(═O)(Q₆₀₁)(Q₆₀₂),

wherein Q₆₀₁ to Q₆₀₃ may each independently be a C₁-C₁₀ alkyl group, aC₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenylgroup, or a naphthyl group, and

xe21 may be an integer from 1 to 5.

In some embodiments, at least one selected from Ar₆₀₁(s) in the numberof xe11 and R₆₀₁(s) in the number of xe21 may include the πelectron-depleted nitrogen-containing ring.

In some embodiments, in Formula 601, ring Ar₆₀₁ may be selected from:

a benzene group, a naphthalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, a dibenzofuran group, adibenzothiophene group, a carbazole group, an imidazole group, apyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an indazole group, a purine group,a quinoline group, an isoquinoline group, a benzoquinoline group, aphthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an isobenzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, and an azacarbazole group; and

a benzene group, a naphthalene group, a fluorene group, aspiro-bifluorene group, a benzofluorene group, a dibenzofluorene group,a phenalene group, a phenanthrene group, an anthracene group, afluoranthene group, a triphenylene group, a pyrene group, a chrysenegroup, a naphthacene group, a picene group, a perylene group, apentaphene group, an indenoanthracene group, a dibenzofuran group, adibenzothiophene group, a carbazole group, an imidazole group, apyrazole group, a thiazole group, an isothiazole group, an oxazolegroup, an isoxazole group, a pyridine group, a pyrazine group, apyrimidine group, a pyridazine group, an indazole group, a purine group,a quinoline group, an isoquinoline group, a benzoquinoline group, aphthalazine group, a naphthyridine group, a quinoxaline group, aquinazoline group, a cinnoline group, a phenanthridine group, anacridine group, a phenanthroline group, a phenazine group, abenzimidazole group, an isobenzothiazole group, a benzoxazole group, anisobenzoxazole group, a triazole group, a tetrazole group, an oxadiazolegroup, a triazine group, a thiadiazole group, an imidazopyridine group,an imidazopyrimidine group, and an azacarbazole group, each substitutedwith at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, aphenyl group, a biphenyl group, a terphenyl group, a naphthyl group,—Si(Q₃₁)(Q₃₂)(Q₃₃), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

When xe11 in Formula 601 is 2 or greater, at least two Ar₆₀₁(s) may bebound via a single bond.

In one or more embodiments, Ar₆₀₁ in Formula 601 may be an anthracenegroup.

In some embodiments, the compound represented by Formula 601 may berepresented by Formula 601-1:

wherein, in Formula 601-1,

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N orC(R₆₁₆), at least one selected from X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ may each independently be understood by referring to thedescription of L₆₀₁ provided herein,

xe611 to xe613 may each independently be understood by referring to thedescription of xe1 provided herein,

R₆₁₁ to R₆₁₃ may each independently be understood by referring to thedescription of R₆₀₁ provided herein, and

R₆₁₄ to R₆₁₆ may each independently be selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, and a naphthyl group.

In some embodiments, in Formulae 601 and 601-1, L₆₀₁ and L₆₁₁ to L₆₁₃may each independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, aspiro-bifluorenylene group, a benzofluorenylene group, adibenzofluorenylene group, a phenanthrenylene group, an anthracenylenegroup, a fluoranthenylene group, a triphenylenylene group, a pyrenylenegroup, a chrysenylene group, a perylenylene group, a pentaphenylenegroup, a hexacenylene group, a pentacenylene group, a thiophenylenegroup, a furanylene group, a carbazolylene group, an indolylene group,an isoindolylene group, a benzofuranylene group, a benzothiophenylenegroup, a dibenzofuranylene group, a dibenzothiophenylene group, abenzocarbazolylene group, a dibenzocarbazolylene group, adibenzosilolylene group, a pyridinylene group, an imidazolylene group, apyrazolylene group, a thiazolylene group, an isothiazolylene group, anoxazolylene group, an isoxazolylene group, a thiadiazolylene group, anoxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, apyridazinylene group, a triazinylene group, a quinolinylene group, anisoquinolinylene group, a benzoquinolinylene group, a phthalazinylenegroup, a naphthyridinylene group, a quinoxalinylene group, aquinazolinylene group, a cinnolinylene group, a phenanthridinylenegroup, an acridinylene group, a phenanthrolinylene group, aphenazinylene group, a benzimidazolylene group, an isobenzothiazolylenegroup, a benzoxazolylene group, an isobenzoxazolylene group, atriazolylene group, a tetrazolylene group, an imidazopyridinylene group,an imidazopyrimidinylene group, and an azacarbazolylene group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, anaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, abenzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group,an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, apyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenylgroup, a hexacenyl group, a pentacenyl group, a thiophenyl group, afuranyl group, a carbazolyl group, an indolyl group, an isoindolylgroup, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranylgroup, a dibenzothiophenyl group, a benzocarbazolyl group, adibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, animidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolylgroup, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, anoxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinylgroup, a triazinyl group, a quinolinyl group, an isoquinolinyl group, abenzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, aquinoxalinyl group, a quinazolinyl group, a cinnolinyl group, aphenanthridinyl group, an acridinyl group, a phenanthrolinyl group, aphenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, abenzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, atetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinylgroup, and an azacarbazolyl group,

but the present disclosure is not limited thereto.

In one or more embodiments, in Formulae 601 and 601-1, xe1 and xe611 toxe613 may each independently be 0, 1, or 2.

In one or more embodiments, in Formulae 601 and 601-1, R₆₀₁ and R₆₁₁ toR₆₁₃ may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, afluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, adibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, afluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenylgroup, a perylenyl group, a pentaphenyl group, a hexacenyl group, apentacenyl group, a thiophenyl group, a furanyl group, a carbazolylgroup, an indolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, aterphenyl group, a naphthyl group, a fluorenyl group, aspiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenylgroup, a phenanthrenyl group, an anthracenyl group, a fluoranthenylgroup, a triphenylenyl group, a pyrenyl group, a chrysenyl group, aperylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenylgroup, a thiophenyl group, a furanyl group, a carbazolyl group, anindolyl group, an isoindolyl group, a benzofuranyl group, abenzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenylgroup, a benzocarbazolyl group, a dibenzocarbazolyl group, adibenzosilolyl group, a pyridinyl group, an imidazolyl group, apyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolylgroup, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group,a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, an isoquinolinyl group, a benzoquinolinylgroup, a phthalazinyl group, a naphthyridinyl group, a quinoxalinylgroup, a quinazolinyl group, a cinnolinyl group, a phenanthridinylgroup, an acridinyl group, a phenanthrolinyl group, a phenazinyl group,a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolylgroup, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group,an imidazopyridinyl group, an imidazopyrimidinyl group, and anazacarbazolyl group; and

—S(═O)₂(Q₆₀₁) and —P(═O)(Q₆₀₁)(Q₆₀₂),

wherein Q₆₀₁ and Q₆₀₂ may respectively be understood by referring to thedescriptions of Q₆₀₁ and Q₆₀₂ provided herein.

The electron transport region may include at least one compound selectedfrom Compounds ET1 to ET39, but the present disclosure is not limitedthereto:

In some embodiments, the electron transport region may include at leastone compound selected from 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline(BCP), 4,7-diphenyl-1,10-phenanthroline (Bphen), Alq₃, BAlq,3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole(TAZ), NTAZ,2,2′,2″-(1,3,5-benzinetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi),4,4′-bis(4,6-diphenyl-1,3,5-triazin-2-yl)biphenyl (BTB), and1,3,5-tris(3-pyridyl-3-phenyl)benzene (TmPyPB):

The thicknesses of the buffer layer, the hole blocking layer, or theelectron control layer may each independently be in a range of about 10Å to about 1,000 Å, and in some embodiments, about 30 Å to about 300 Å.When the thicknesses of the buffer layer, the hole blocking layer or theelectron control layer are within any of the foregoing ranges, excellenthole blocking characteristics or excellent electron controllingcharacteristics may be obtained without a substantial increase indriving voltage.

The thickness of the electron transport layer may be in a range of about100 Å to about 3,000 Å, and in some embodiments, about 150 Å to about500 Å. When the thickness of the electron transport layer is within anyof the foregoing ranges, excellent electron transport characteristicsmay be obtained without a substantial increase in driving voltage.

The electron transport region (for example, the electron transport layerin the electron transport region) may further include, in addition tothe materials described above, a metal-containing material.

The metal-containing material may include at least one selected from analkali metal complex and an alkaline earth metal complex. The alkalimetal complex may include a metal ion selected from a lithium (Li) ion,a sodium (Na) ion, a potassium (K) ion, a rubidium (Rb) ion, and acesium (Cs) ion. The alkaline earth metal complex may include a metalion selected from a beryllium (Be) ion, a magnesium (Mg) ion, a calcium(Ca) ion, a strontium (Sr) ion, and a barium (Ba) ion. Each ligandcoordinated with the metal ion of the alkali metal complex and thealkaline earth metal complex may independently be selected fromhydroxyquinoline, hydroxyisoquinoline, hydroxybenzoquinoline,hydroxyacridine, hydroxyphenanthridine, hydroxyphenyloxazole,hydroxyphenylthiazole, hydroxyphenyloxadiazole,hydroxyphenylthiadiazole, hydroxyphenylpyridine,hydroxyphenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine,phenanthroline, and cyclopentadiene, but the present disclosure is notlimited thereto.

For example, the metal-containing material may include a Li complex. TheLi complex may include, e.g., Compound ET-D1 (LiQ) or Compound ET-D2:

The electron transport region may include an electron injection layerthat facilitates injection of electrons from the second electrode 190.The electron injection layer may be in direct contact (e.g., physicalcontact) with the second electrode 190.

The electron injection layer may have i) a single-layered structureincluding (or consisting of) a single layer including (or consisting of)a single material, ii) a single-layered structure including (orconsisting of) a single layer including a plurality of differentmaterials, or iii) a multi-layered structure having a plurality oflayers, each including a plurality of different materials.

The electron injection layer may include an alkali metal, an alkalineearth metal, a rare earth metal, an alkali metal compound, an alkalineearth metal compound, a rare earth metal compound, an alkali metalcomplex, an alkaline earth metal complex, a rare earth metal complex, ora combination thereof.

The alkali metal may be selected from Li, Na, K, Rb, and Cs. In someembodiments, the alkali metal may be Li, Na, or Cs. In one or moreembodiments, the alkali metal may be Li or Cs, but the presentdisclosure is not limited thereto.

The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.

The rare earth metal may be selected from Sc, Y, Ce, Tb, Yb, and Gd.

The alkali metal compound, the alkaline earth metal compound, and therare earth metal compound may each independently be selected from oxidesand halides (e.g., fluorides, chlorides, bromides, or iodines) of thealkali metal, the alkaline earth metal, and the rare earth metal,respectively.

The alkali metal compound may be selected from alkali metal oxides, suchas Li₂O, Cs₂O, or K₂O, and alkali metal halides, such as LiF, NaF, CsF,KF, LiI, NaI, CsI, or KI. In some embodiments, the alkali metal compoundmay be selected from LiF, Li₂O, NaF, LiI, NaI, CsI, and KI, but thepresent disclosure is not limited thereto.

The alkaline earth-metal compound may be selected from alkalineearth-metal compounds, such as BaO, SrO, CaO, BaxSr_(1-x)O (wherein0<x<1), and Ba_(x)Ca_(1-x)O (wherein 0<x<1). In some embodiments, thealkaline earth metal compound may be selected from BaO, SrO, and CaO,but the present disclosure is not limited thereto.

The rare earth metal compound may be selected from YbF₃, ScF₃, Sc₂O₃,Y₂O₃, Ce₂O₃, GdF₃, and TbF₃. In some embodiments, the rare earth metalcompound may be selected from YbF₃, ScF₃, TbF₃, YbI₃, ScI₃, and TbI₃,but the present disclosure is not limited thereto.

The alkali metal complex, the alkaline earth metal complex, and the rareearth metal complex may each include ions of the above-described alkalimetal, alkaline earth metal, and rare earth metal. Each ligandcoordinated with the metal ion of the alkali metal complex, the alkalineearth metal complex, and the rare earth metal complex may independentlybe selected from hydroxyquinoline, hydroxyisoquinoline,hydroxybenzoquinoline, hydroxyacridine, hydroxyphenanthridine,hydroxyphenyloxazole, hydroxyphenylthiazole, hydroxyphenyloxadiazole,hydroxyphenylthiadiazole, hydroxyphenylpyridine,hydroxyphenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine,phenanthroline, and cyclopentadiene, but the present disclosure is notlimited thereto.

The electron injection layer may include (or consist of) an alkalimetal, an alkaline earth metal, a rare earth metal, an alkali metalcompound, an alkaline earth metal compound, a rare earth metal compound,an alkali metal complex, an alkaline earth metal complex, a rare earthmetal complex, or a combination thereof, as described above. In someembodiments, the electron injection layer may further include an organicmaterial. When the electron injection layer further includes an organicmaterial, the alkali metal, the alkaline earth metal, the rare earthmetal, the alkali metal compound, the alkaline earth metal compound, therare earth metal compound, the alkali metal complex, the alkaline earthmetal complex, the rare earth metal complex, or a combination thereofmay be homogeneously or non-homogeneously dispersed in a matrixincluding the organic material.

The thickness of the electron injection layer may be in a range of about1 Å to about 100 Å, and in some embodiments, about 3 Å to about 90 Å.When the thickness of the electron injection layer is within any of theforegoing ranges, excellent electron injection characteristics may beobtained without a substantial increase in driving voltage.

n-Dopant

The electron transport region may include a charge generating materialsuch as an n-dopant as well as the aforementioned materials, to improveconductive properties of the hole transport region. The chargegenerating material may be substantially homogeneously ornon-homogeneously dispersed in the electron transport region.

The n-dopant may be a molecule and/or a neutral radical having a highestoccupied molecular orbital (HOMO) of −3.3 eV or higher, or for example,−2.8 eV or higher (higher positive number). The HOMO of the n-dopant maybe determined by cyclic voltammetry measurement of the oxidationpotential.

In some embodiments, the n-dopant may include at least one selected fromCompounds 701 to 706, but the present disclosure is not limited thereto:

Second Electrode 190

The second electrode 190 may be on the organic layer 150. In anembodiment, the second electrode 190 may be a cathode that is anelectron injection electrode. In this embodiment, a material for formingthe second electrode 190 may be a material having a low work function,for example, a metal, an alloy, an electrically conductive compound, ora combination thereof.

The second electrode 190 may include at least one selected from lithium(Li), silver (Ag), magnesium (Mg), aluminum (AI), aluminum-lithium(Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver(Mg—Ag), ITO, and IZO, but the present disclosure is not limitedthereto. The second electrode 190 may be a transmissive electrode, asemi-transmissive electrode, or a reflective electrode.

The second electrode 190 may have a single-layered structure, or amulti-layered structure including two or more layers.

Description of FIGS. 2 to 4

Referring to FIG. 2, an organic light-emitting device 20 has a firstcapping layer 210, the first electrode 110, the organic layer 150, andthe second electrode 190 structure, wherein the layers are sequentiallystacked in this stated order. Referring to FIG. 3, an organiclight-emitting device 30 has the first electrode 110, the organic layer150, the second electrode 190, and a second capping layer 220 structure,wherein the layers are sequentially stacked in this stated order.Referring to FIG. 4, an organic light-emitting device 40 has the firstcapping layer 210, the first electrode 110, the organic layer 150, thesecond electrode 190, and the second capping layer 220 structure,wherein the layers are stacked in this stated order.

The first electrode 110, the organic layer 150, and the second electrode190 illustrated in FIGS. 2 to 4 may be substantially the same as thoseillustrated in FIG. 1.

In the organic light-emitting devices 20 and 40, light emitted from theemission layer in the organic layer 150 may pass through the firstelectrode 110 (which may be a semi-transmissive electrode or atransmissive electrode) and through the first capping layer 210 to theoutside. In the organic light-emitting devices 30 and 40, light emittedfrom the emission layer in the organic layer 150 may pass through thesecond electrode 190 (which may be a semi-transmissive electrode or atransmissive electrode) and through the second capping layer 220 to theoutside.

The first capping layer 210 and the second capping layer 220 may improvethe external luminescence efficiency based on the principle ofconstructive interference.

The first capping layer 210 and the second capping layer 220 may eachindependently have a refractive index of 1.6 or greater at a wavelengthof 589 nm.

The first capping layer 210 and the second capping layer 220 may eachindependently be a capping layer including an organic material, aninorganic capping layer including an inorganic material, or a compositecapping layer including an organic material and an inorganic material.

At least one selected from the first capping layer 210 and the secondcapping layer 220 may each independently include at least one materialselected from carbocyclic compounds, heterocyclic compounds, amine-basedcompounds, porphine derivatives, phthalocyanine derivatives,naphthalocyanine derivatives, alkali metal complexes, and alkaline earthmetal complexes. The carbocyclic compound, the heterocyclic compound,and the amine group-containing compound may optionally be substitutedwith a substituent containing at least one element selected from O, N,S, Se, Si, F, Cl, Br, and I. In some embodiments, at least one selectedfrom the first capping layer 210 and the second capping layer 220 mayeach independently include an amine-based compound.

In one or more embodiments, at least one selected from the first cappinglayer 210 and the second capping layer 220 may each independentlyinclude a compound represented by Formula 201 or a compound representedby 202.

In one or more embodiments, at least one selected from the first cappinglayer 210 and the second capping layer 220 may each independentlyinclude a compound selected from Compounds HT28 to HT33 and Compound CP1to CP5, but the present disclosure is not limited thereto:

Hereinbefore, the organic light-emitting device has been described withreference to FIGS. 1 to 4, but the present disclosure is not limitedthereto.

The layers constituting the hole transport region, the emission layer,and the layers constituting the electron transport region may be formedin a set or specific region by using one or more suitable methods suchas vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB)deposition, ink-jet printing, laser printing, and/or laser-inducedthermal imaging.

When the layers constituting the hole transport region, the emissionlayer, and the layers constituting the electron transport region areeach formed by vacuum deposition, the vacuum deposition may be performedat a deposition temperature in a range of about 100° C. to about 500° C.at a vacuum degree in a range of about 10⁻⁸ torr to about 10⁻³ torr, andat a deposition rate in a range of about 0.01 Angstroms per second(Å/sec) to about 100 Å/sec, depending on the material to be included ineach layer and the structure of each layer to be formed.

When the layers constituting the hole transport region, the emissionlayer, and the layers constituting the electron transport region areeach formed by spin coating, the spin coating may be performed at acoating rate of about 2,000 revolutions per minute (rpm) to about 5,000rpm and at a heat treatment temperature of about 80° C.° C. to about200° C., depending on the material to be included in each layer and thestructure of each layer to be formed.

Electronic Apparatus

The organic light-emitting device may be included in various suitableelectronic apparatuses. In some embodiments, an electronic apparatusincluding the organic light-emitting device may be an emission apparatusor an authentication apparatus.

The electronic apparatus (e.g., an emission apparatus) may furtherinclude, in addition to the organic light-emitting device, i) a colorfilter, ii) a color-conversion layer, or iii) a color filter and acolor-conversion layer. The color filter and/or the color-conversionlayer may be on at least one traveling direction of light emitted fromthe organic light-emitting device. For example, light emitted from theorganic light-emitting device may be blue light or white light. Theorganic light-emitting device may be understood by referring to thedescription of the organic light-emitting device provided herein. Insome embodiments, the color-conversion layer may include a quantum dot.The quantum dot may be, for example, the quantum dot described herein.

The electronic apparatus may include a first substrate. The firstsubstrate may include a plurality of sub-pixel areas, the color filtermay include a plurality of color filter areas respectively correspondingto the plurality of sub-pixel areas, and the color-conversion layer mayinclude a plurality of color-conversion areas respectively correspondingto the plurality of sub-pixel areas.

A pixel defining film may be located between the plurality of sub-pixelareas to define each sub-pixel area.

The color filter may further include a plurality of color filter areasand light-blocking patterns between the plurality of color filter areas,and the color-conversion layer may further include a plurality ofcolor-conversion areas and light-blocking patterns between the pluralityof color-conversion areas.

The plurality of color filter areas (or a plurality of color-conversionareas) may include: a first area emitting first color light; a secondarea emitting second color light; and/or a third area emitting thirdcolor light, and the first color light, the second color light, and/orthe third color light may have different maximum emission wavelengths.In some embodiments, the first color light may be red light, the secondcolor light may be green light, and the third color light may be bluelight. In some embodiments, the plurality of color filter areas (or theplurality of color-conversion areas) may each include a quantum dot. Insome embodiments, the first area may include a red quantum dot, thesecond area may include a green quantum dot, and the third area may notinclude a quantum dot. The quantum dot may be understood by referring tothe description of the quantum dot provided herein. The first area, thesecond area, and/or the third area may each further include an emitter.

In some embodiments, the organic light-emitting device may emit firstlight, the first area may absorb the first light to emit 1-1 colorlight, the second area may absorb the first light to emit 2-1 colorlight, and the third area may absorb the first light to emit 3-1 colorlight. In this embodiment, the 1-1 color light, the 2-1 color light, andthe 3-1 color light may each have a different maximum emissionwavelength. In some embodiments, the first light may be blue light, the1-1 color light may be red light, the 2-1 color light may be greenlight, and the 3-1 light may be blue light.

The electronic apparatus may further include a thin-film transistor, inaddition to the organic light-emitting device. The thin-film transistormay include a source electrode, a drain electrode, and an activationlayer, wherein one selected from the source electrode and the drainelectrode may be electrically coupled to one of the first electrode andthe second electrode of the organic light-emitting device.

The thin-film transistor may further include a gate electrode, a gateinsulating film, and/or the like.

The activation layer may include a crystalline silicon, an amorphoussilicon, an organic semiconductor, and/or an oxide semiconductor.

The electronic apparatus may further include a sealing portion forsealing the organic light-emitting device. The sealing portion may belocated between the color filter and/or the color-conversion layer andthe organic light-emitting device. The sealing portion may allow lightto pass to the outside from the organic light-emitting device andprevent or reduce the permeation of the air and moisture into theorganic light-emitting device at the same time. The sealing portion maybe a sealing substrate including a transparent glass and/or a plasticsubstrate. The sealing portion may be a thin-film encapsulating layerincluding at least one selected from an organic layer and an inorganiclayer. When the sealing portion is a thin film encapsulating layer, theelectronic apparatus may be flexible.

In addition to the color filter and/or the color-conversion layer,various suitable functional layers may be on the sealing portiondepending on the use of an electronic apparatus. Examples of thefunctional layer may include a touch screen layer, a polarization layer,and/or the like. The touch screen layer may be a resistive touch screenlayer, a capacitive touch screen layer, and/or an infrared beam touchscreen layer. The authentication apparatus may be, for example, abiometric authentication apparatus that identifies an individualaccording biometric information (e.g., a fingertip, a pupil, and/or thelike).

The authentication apparatus may further include a biometric informationcollecting unit, in addition to the organic light-emitting devicedescribed above.

The electronic apparatus may be applicable to various suitable displays,an optical source, lighting, a personal computer (e.g., a mobilepersonal computer), a cellphone, a digital camera, an electronic note,an electronic dictionary, an electronic game console, a medical device(e.g., an electronic thermometer, a blood pressure meter, a glucometer,a pulse measuring device, a pulse wave measuring device, anelectrocardiograph recorder, an ultrasonic diagnosis device, and/or anendoscope display device), a fish finder, various suitable measurementdevices, gauges (e.g., gauges of an automobile, an airplane, and/or aship), and/or a projector.

General Definitions of Substituents

The term “C₁-C₆₀ alkyl group,” as used herein, refers to a linear orbranched aliphatic hydrocarbon monovalent group having 1 to 60 carbonatoms. Examples thereof include a methyl group, an ethyl group, a propylgroup, an iso-butyl group, a sec-butyl group, a tert-butyl group, apentyl group, an iso-amyl group, and a hexyl group. The term “C₁-C₆₀alkylene group,” as used herein, refers to a divalent group havingsubstantially the same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group,” as used herein, refers to a hydrocarbongroup having at least one carbon-carbon double bond at a main chain(e.g., in the middle) or at a terminal end (e.g., the terminus) of theC₂-C₆₀ alkyl group. Examples thereof include an ethenyl group, apropenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group,”as used herein, refers to a divalent group having substantially the samestructure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group,” as used herein, refers to a hydrocarbongroup having at least one carbon-carbon triple bond at a main chain(e.g., in the middle) or at a terminal end (e.g., the terminus) of theC₂-C₆₀ alkyl group. Examples thereof include an ethynyl group and apropynyl group. The term “C₂-C₆₀ alkynylene group,” as used herein,refers to a divalent group having substantially the same structure asthe C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group,” as used herein, refers to a monovalentgroup represented by —OA₁₀₁ (wherein A₁₀₁ is a C₁-C₁ alkyl group).Examples thereof include a methoxy group, an ethoxy group, and anisopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group,” as used herein, refers to amonovalent monocyclic saturated hydrocarbon group including 3 to 10carbon atoms. Examples thereof include a cyclopropyl group, a cyclobutylgroup, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.The term “C₃-C₁₀ cycloalkylene group,” as used herein, refers to adivalent group having substantially the same structure as the C₃-C₁₀cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group,” as used herein, refers to amonovalent monocyclic group including at least one heteroatom selectedfrom N, O, Si, P, and S as a ring-forming atom and 1 to 10 carbon atoms.Examples thereof include a 1,2,3,4-oxatriazolidinyl group, atetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term“C₁-C₁₀ heterocycloalkylene group,” as used herein, refers to a divalentgroup having substantially the same structure as the C₁-C₁₀heterocycloalkyl group.

The term “C₃-C₁₀ cycloalkenyl group,” as used herein, refers to amonovalent monocyclic group that has 3 to 10 carbon atoms and at leastone double bond in its ring, and is not aromatic. Examples thereofinclude a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenylgroup. The term “C₃-C₁₀ cycloalkenylene group,” as used herein, refersto a divalent group having substantially the same structure as theC₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group,” as used herein, refers to amonovalent monocyclic group including at least one heteroatom selectedfrom N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms,and at least one double bond in its ring. Examples of the C₁-C₁₀heterocycloalkenyl group include a 4,5-dihydro-1,2,3,4-oxatriazolylgroup, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group.The term “C₁-C₁₀ heterocycloalkylene group,” as used herein, refers to adivalent group having substantially the same structure as the C₁-C₁₀heterocycloalkyl group.

The term “C₆-C₆₀ aryl group,” as used herein, refers to a monovalentgroup having a carbocyclic aromatic system having 6 to 6 carbon atoms.The term “C₆-C₆₀ arylene group,” as used herein, refers to a divalentgroup having a carbocyclic aromatic system having 6 to 60 carbon atoms.Examples of the C₆-C₆₀ aryl group include a fluorenyl group, a phenylgroup, a naphthyl group, an anthracenyl group, a phenanthrenyl group, apyrenyl group, and a chrysenyl group. When the C₆-C₆₀ aryl group and theC₆-C₆₀ arylene group each independently include two or more rings, therespective rings may be fused (e.g., combined together).

The term “C₁-C₆₀ heteroaryl group,” as used herein, refers to amonovalent group having a heterocyclic aromatic system having at leastone heteroatom selected from N, O, Si, P, and S as a ring-forming atomand 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group,” as usedherein, refers to a divalent group having a heterocyclic aromatic systemhaving at least one heteroatom selected from N, O, Si, P, and S as aring-forming atom and 1 to 60 carbon atoms. Examples of the C₁-C₆₀heteroaryl group include a carbazolyl group, a pyridinyl group, apyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinylgroup, a quinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀heteroaryl group and the C₁-C₆₀ heteroarylene group each independentlyinclude two or more rings, the respective rings may be fused (e.g.,combined together).

The term “C₆-C₆₀ aryloxy group,” as used herein, is represented by—OA₁₀₂ (wherein A₁₀₂ is the C₆-C₆₀ aryl group). The term “C₆-C₆₀arylthio group,” as used herein, is represented by —SA₁₀₃ (wherein A₁₀₃is the C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group,” as usedherein, refers to a monovalent group that has two or more ringscondensed and only carbon atoms as ring forming atoms (e.g., 8 to 60carbon atoms), wherein the entire molecular structure is non-aromatic.Examples of the monovalent non-aromatic condensed polycyclic group mayinclude an adamantyl group. The term “divalent non-aromatic condensedpolycyclic group,” as used herein, refers to a divalent group havingsubstantially the same structure as the monovalent non-aromaticcondensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group,” asused herein, refers to a monovalent group that has two or more condensedrings and at least one heteroatom selected from N, O, Si, P, and S, inaddition to carbon atoms (e.g., 1 to 60 carbon atoms), as a ring-formingatom, wherein the entire molecular structure is non-aromatic. Examplesof the monovalent non-aromatic condensed heteropolycyclic group mayinclude an azaadamantyl group. The term “divalent non-aromatic condensedheteropolycyclic group,” as used herein, refers to a divalent grouphaving substantially the same structure as the monovalent non-aromaticcondensed heteropolycyclic group.

The term “C₅-C₆₀ carbocyclic group,” as used herein, refers to amonocyclic or polycyclic group having 5 to 60 carbon atoms only asring-forming atoms, and the term “C₄-C₃₀ carbocyclic group,” as usedrefers to a monocyclic or polycyclic group having 4 to 60 carbon atomsonly as ring-forming atoms. The C₅-C₆₀ carbocyclic group (or the C₄-C₃₀carbocyclic group) may be an aromatic carbocyclic group or anon-aromatic carbocyclic group. The terms “C₅-C₆₀ carbocyclic group” and“C₄-C₃₀ carbocyclic group,” as used herein, refers to a ring (e.g., abenzene group), a monovalent group (e.g., a phenyl group), or a divalentgroup (e.g., a phenylene group). Also, depending on the number ofsubstituents connected to the C₅-C₆₀ carbocyclic group or the C₄-C₃₀carbocyclic group, the C₅-C₆₀ carbocyclic group or the C₄-C₃₀carbocyclic group may be a trivalent group or a quadrivalent group.

The term “C₁-C₆₀ heterocyclic group,” as used herein, refers to a grouphaving substantially the same structure as the C₅-C₆₀ carbocyclic group,except that at least one heteroatom selected from N, O, Si, P, and S isused as a ring-forming atom, in addition to carbon atoms (e.g., 1 to 60carbon atoms).

In the present specification, at least one of substituents of thesubstituted C₅-C₆₀ carbocyclic group (or the substituted C₄-C₃₀carbocyclic group), the substituted C₁-C₆₀ heterocyclic group, thesubstituted C₃-C₁₀ cycloalkylene group, the substituted C₁-C₁₀heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group,the substituted C₁-C₁₀ heterocycloalkenylene group, the substitutedC₆-C₆₀ arylene group, the substituted C₁-C₆₀ heteroarylene group, thesubstituted divalent non-aromatic condensed polycyclic group, thesubstituted divalent non-aromatic condensed heteropolycyclic group, thesubstituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group,the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxygroup, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, thesubstituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ arylgroup, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substitutedmonovalent non-aromatic condensed polycyclic group, and the substitutedmonovalent non-aromatic condensed heteropolycyclic group may be selectedfrom:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group,and a C₁-C₆ alkoxy group, each substituted with at least one selectedfrom deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, anitro group, an amidino group, a hydrazino group, a hydrazono group, aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),—S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently beselected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, acyano group, a nitro group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroarylgroup, a monovalent non-aromatic condensed polycyclic group, amonovalent non-aromatic condensed heteropolycyclic group, a biphenylgroup, and a terphenyl group.

“Ph,” as used herein, represents a phenyl group, “Me,” as used herein,represents a methyl group, “Et,” as used herein, represents an ethylgroup, “ter-Bu” or “Bu^(t),” as used herein, represents a tert-butylgroup, and “OMe,” as used herein, represents a methoxy group.

The term “biphenyl group,” as used herein, refers to a phenyl groupsubstituted with at least one phenyl group. The “biphenyl group” belongsto “a substituted phenyl group” having a “C₆-C₆₀ aryl group” as asubstituent.

The term “terphenyl group,” as used herein, refers to a phenyl groupsubstituted with at least one phenyl group. The “terphenyl group”belongs to “a substituted phenyl group” having a “C₆-C₆₀ aryl groupsubstituted with a C₆-C₆₀ aryl group” as a substituent.

The symbols * and *′, as used herein, unless defined otherwise, refer toa binding site to an adjacent atom in a corresponding formula.

Hereinafter an organic light-emitting device according to an embodimentwill be described in more detail with reference to Examples.

EXAMPLES Comparative Example 1

An anode was manufactured by cutting a Corning 15 Ω/cm² (1,200 Å) ITOglass substrate to a size of 50 mm×50 mm×0.5 mm, ultrasonically cleaningthe glass substrate by using acetone, isopropyl alcohol, and pure waterfor 15 minutes each, and then irradiating UV light for 30 minutesthereto and being exposed to ozone to clean. Then, the anode was loadedinto a vacuum deposition apparatus.

HT18 and Compound 202 (2 percent by weight, wt %) was deposited on theITO glass substrate to a thickness of 100 Å to form a hole injectionlayer, and HT18 was deposited on the hole injection layer to a thicknessof 1,000 Å to form a hole transport layer.

TCTA was deposited on the hole transport layer to a thickness of 100 Åto form an electron blocking layer, thereby forming a hole transportregion.

CBP as a host and BD1 (at a concentration of 10 vol %) as a dopant wereco-deposited on the hole transport region to form an emission layerhaving a thickness of 300 Å.

DIC-TRZ was deposited on the emission layer to form a hole blockinglayer having a thickness of 50 Å, and ET1 and Liq were deposited to aweight ratio of 1:1 to form an electron transport layer having athickness of 300 Å.

LiF was deposited on the electron transport layer to form an electroninjection layer having a thickness of 10 Å, and Al was deposited to athickness of 120 Å to form a cathode. HT28 was deposited on the cathodeto form a capping layer having a thickness of 800 Å, thereby completingthe manufacture of an organic light-emitting device.

Examples 1 and 2 and Comparative Examples 2 and 3

Organic light-emitting device were manufactured in substantially thesame manner as in Comparative Example 1, except that hosts and dopantsshown in Table 1 were used in the formation of an emission layer.

Examples 3 and 4

Organic light-emitting device were manufactured in substantially thesame manner as in Comparative Example 1, except that the emission layerwas formed as two emission layers in the order of a first emission layerand a second emission layer from the anode by using hosts and dopantsshown in Table 1.

Example 5

Organic light-emitting device were manufactured in substantially thesame manner as in Comparative Example 1, except that the emission layerwas formed as three emission layers in the order of a first emissionlayer, a second emission layer, and a third emission layer from theanode by using hosts and dopants shown in Table 1.

TABLE 1 First emission layer Second emission layer Third emission layerNo. Host Dopant Host Dopant Host Dopant Comparative CBP BD1 (10 — — — —Example 1 (thickness vol %) of 300 Å) Comparative CBP BD2 (10 — — — —Example 2 (thickness vol %) of 300 Å) Comparative CBP Ir(dmp)₃ (10 — — —— Example 3 (thickness vol %) + mer- of 300 Å) Ir(pmp)₃ (3 vol %)Example 1 CBP:DIC- BD1(10 vol %) + — — — — TRZ (6:4) BD2 (1 vol %)(thickness of 300 Å) Example 2 CBP:DIC- BD1(10 vol %) + — — — — TRZ(6:4) BD2 (3 vol %) (thickness of 300 Å) Example 3 CBP:DIC- BD1 (10CBP:DIC- BD2 (10 — — TRZ (6:4) vol %) TRZ (6:4) vol %) (thickness(thickness of 100 Å) of 100 Å) Example 4 CBP:DIC- BD2 (10 CBP:DIC- BD1(10 — — TRZ (6:4) vol %) TRZ (6:4) vol %) (thickness (thickness of 100Å) of 200 Å) Example 5 CBP:DIC- BD2 (10 CBP:DIC- BD1 (10 CBP:DIC- BD2(10 TRZ (6:4) vol %) TRZ (5:5) vol %) TRZ (4:6) vol %) (thickness(thickness (thickness of 100 Å) of 100 Å) of 100 Å)

Evaluation Example

The driving voltage (V), current efficiency (Cd/A), and lifespan (T95)of the organic light-emitting devices of Examples 1 to 5 and ComparativeExamples 1 to 3 were measured at a luminance of 1,000 nit. The resultsthereof are shown in Table 2. The driving voltage and efficiency of theorganic light-emitting devices were measured by using a currentvoltmeter Keithley SMU 236 and a luminance meter PR650. The lifespanindicates a time (hour) for the luminance of the organic light-emittingdevice to decline to 95% of its initial luminance.

TABLE 2 T95 lifespan Driving voltage Efficiency (@1,000 nit) No. (V)CIE_y (Cd/A) (h) Comparative 6.1 0.052 18.3 49 Example 1 Comparative 5.90.063 18.8 62 Example 2 Comparative 6.8 0.112 13.1 9 Example 3 Example 16.1 0.053 18.5 60 Example 2 6.0 0.055 18.8 75 Example 3 6.0 0.057 18.855 Example 4 5.9 0.055 19.1 71 Example 5 5.6 0.053 19.3 78

As shown in Table 2, the organic light-emitting devices of Examples 1 to5 exhibited improved driving voltage, color purity, efficiency, and/orlifespan, as compared with the organic light-emitting devices ofComparative Examples 1 to 3.

As is apparent from the foregoing description, the organiclight-emitting device may have high color purity, high efficiency, andlong lifespan.

It should be understood that embodiments described herein should beconsidered in a descriptive sense only and not for purposes oflimitation. Descriptions of features or aspects within each embodimentshould typically be considered as available for other similar featuresor aspects in other embodiments. While one or more embodiments have beendescribed with reference to the figures, it will be understood by thoseof ordinary skill in the art that various changes in form and detailsmay be made therein without departing from the spirit and scope of thepresent disclosure as defined by the following claims, and equivalents.

What is claimed is:
 1. An organic light-emitting device comprising: afirst electrode; a second electrode facing the first electrode; and anorganic layer between the first electrode and the second electrode andcomprising an emission layer, wherein the emission layer comprises ahost and a dopant, the host comprises a first compound and a secondcompound different from the first compound, the dopant comprises a thirdcompound and a fourth compound different from the third compound, andthe third compound is a platinum-containing organometallic compound. 2.The organic light-emitting device of claim 1, wherein a weight ratio ofthe third compound to the fourth compound in the emission layer is in arange of about 100:1 to about 1:100.
 3. The organic light-emittingdevice of claim 1, wherein a y coordinate among CIE color-coordinates oflight emitted from the emission layer is in a range of about 0.045 toabout 0.06.
 4. The organic light-emitting device of claim 1, wherein thefirst compound is a hole-transporting host, and the second compound isan electron-transporting host.
 5. The organic light-emitting device ofclaim 1, wherein the first compound comprises at least one moietyrepresented by any one selected from Formulae 3-1 to 3-3:

wherein, in Formulae 3-1 to 3-3, X₃₁ is selected from O, S,N-(L₃₃)_(a33)-(R₃₃)_(b33), C(R₃₃)(R₃₄), and Si(R₃₃)(R₃₄), CY₃₁ and CY₃₂are each independently a π-electron rich cyclic group, L₃₃ is selectedfrom a single bond, a substituted or unsubstituted C₅-C₃₀ carbocyclicgroup, and a substituted or unsubstituted C₁-C₃₀ heterocyclic group, a33is an integer from 1 to 10, R₃₃ and R₃₄ are each independently selectedfrom hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a carboxylic acid group or a salt thereof, a sulfonic acid groupor a salt thereof, a phosphoric acid group or a salt thereof, asubstituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂), —B(Q₁)(Q₂),—C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), b33 is an integer from 1 to10, and *, *′, and *″ each indicate a binding site to an adjacent atom.6. The organic light-emitting device of claim 1, wherein the firstcompound is selected from compounds represented by Formulae 3-11 to3-14:

wherein, in Formula 3-11, CY₃₁ and ring CY₃₂ are each independently aπ-electron rich cyclic group having 3 to 30 carbon atoms, X₃₁ isselected from O, S, N-(L₃₃)_(a33)-(R₃₃)_(b33), C(R₃₃)(R₃₄), andSi(R₃₃)(R₃₄), c31 and c32 are each independently an integer from 0 to 3,wherein, in Formulae 3-11 to 3-14, L₃₁ to L₃₃ and L₄₁ to L₄₇ are eachindependently selected from a single bond, a substituted orunsubstituted C₅-C₃₀ carbocyclic group, and a substituted orunsubstituted C₁-C₃₀ heterocyclic group, a31 to a33 and a41 to a47 areeach independently an integer from 1 to 10, R₃₁ to R₃₄ and R₄₁ to R₄₆are each independently selected from hydrogen, deuterium, —F, —Cl, —Br,—I, a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkylgroup, a substituted or unsubstituted C₂-C₆₀ alkenyl group, asubstituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂),—B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), b31 to b33 andb41 to b46 are each independently an integer from 1 to 10, and at leastone substituent of the substituted C₅-C₃₀ carbocyclic group, thesubstituted C₁-C₃₀ heterocyclic group, the substituted C₁-C₆ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₁-C₆₀ heteroaryl group, the substituted monovalentnon-aromatic condensed polycyclic group, and the substituted monovalentnon-aromatic condensed heteropolycyclic group is selected from:deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and aC₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, aC₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted withat least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxylgroup, a cyano group, a nitro group, an amidino group, a hydrazinogroup, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂),—B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group; a C₃-C₁₀ cycloalkylgroup, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),—B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ toQ₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl groupsubstituted with a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group substitutedwith a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, a biphenyl group, and a terphenylgroup.
 7. The organic light-emitting device of claim 1, wherein thesecond compound comprises an electron-transporting moiety comprising atleast one selected from —F, a cyano group, a C₁-C₆₀ alkyl groupsubstituted with —F or a cyano group, a C₆-C₆₀ aryl group substitutedwith —F or a cyano group, and a π-electron-depleted nitrogen-containingcyclic group.
 8. The organic light-emitting device of claim 1, whereinthe second compound is a compound represented by Formula 4-1:

wherein, in Formula 4-1, X₅₁ is N or C[(L₅₄)_(a54)-(R₅₄)_(b54)], X₅₂ isN or C[(L₅₅)_(a55)-(R₅₅)_(b55)], and X₅₃ is N orC[(L₅₆)_(a56)-(R₅₆)_(b56)], L₅₁ to L₅₆ are each independently selectedfrom a single bond, a substituted or unsubstituted C₅-C₃₀ carbocyclicgroup, and a substituted or unsubstituted C₁-C₃₀ heterocyclic group, a51to a56 are each independently an integer from 1 to 10, R₅₁ to R₅₆ areeach independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a carboxylic acid group or a saltthereof, a sulfonic acid group or a salt thereof, a phosphoric acidgroup or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkylgroup, a substituted or unsubstituted C₂-C₆₀ alkenyl group, asubstituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N(Q₁)(Q₂),—B(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), b51 to b56 areeach independently an integer from 1 to 10, and at least one substituentof the substituted C₅-C₃₀ carbocyclic group, the substituted C₁-C₃₀heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substitutedC₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, thesubstituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkylgroup, the substituted C₁-C₁₀ heterocycloalkyl group, the substitutedC₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenylgroup, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxygroup, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensedpolycyclic group, and the substituted monovalent non-aromatic condensedheteropolycyclic group is selected from: deuterium, —F, —Cl, —Br, —I, ahydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; aC₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, anda C₁-C₆₀ alkoxy group, each substituted with at least one selected fromdeuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃),—N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and—P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkylgroup, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, aC₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, aC₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclicgroup, and a monovalent non-aromatic condensed heteropolycyclic group; aC₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ arylgroup, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀heteroaryl group, a monovalent non-aromatic condensed polycyclic group,and a monovalent non-aromatic condensed heteropolycyclic group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, a monovalentnon-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃),—N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and—P(═O)(Q₂₁)(Q₂₂); and —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂),—C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amino group, an amidino group, a hydrazino group, ahydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, aC₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl groupsubstituted with a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group substitutedwith a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, a biphenyl group, and a terphenylgroup.
 9. The organic light-emitting device of claim 1, wherein thethird compound and the fourth compound are each independently anorganometallic compound represented by Formula 1:

wherein, in Formulae 1 and 1 Å to 1C, M is selected from a first-rowtransition metal, a second-row transition metal, and a third-rowtransition metal, wherein M in the third compound is platinum (Pt), L₁is selected from a ligand represented by Formula 1A, a ligandrepresented by Formula 1B, and a ligand represented by Formula 1C, L₂ isselected from a monodentate ligand, a bidentate ligand, and a tridentateligand, n1 is selected from 1, 2, and 3, n2 is selected from 0, 1, 2, 3,and 4, CY₁ to CY₄ are each independently selected from a C₅-C₃₀carbocyclic group and a C₁-C₃₀ heterocyclic group, Y₁ to Y₄ are eachindependently selected from a single bond, a double bond, a substitutedor unsubstituted C₆-C₃₀ arylene group, a substituted or unsubstitutedC₁-C₃₀ heteroarylene group, *—O—*′, *—S—*′, *—C(═O)—*′, *—S(═O)—*′,*—C(R₅)(R₆)—*′, *—C(R₅)═C(R₆)—*′, *—C(R₅)═*′, *—Si(R₅)(R₆)—*′,*—B(R₅)—*′, *—N(R₅)—*′, and *—P(R₅)—*′, a1 to a3 are each independentlyselected from 1, 2, and 3, a4 is selected from 0, 1, 2, and 3, and whena4 is 0, CY₂ and CY₄ are not connected to each other, T₁ to T₄ are eachindependently selected from a chemical bond, *—O—*′, *—S—*′, *—B(R₇)—*′,*—N(R₇)—*′, *—P(R₇)—*′, *—C(R₇)(R₅)—*′, *—Si(R₇)(R₅)—*′,*—Ge(R₇)(R₈)—*′, *—C(═O)—*′, and *—C(═S)—*′, *₁, *₂, *₃, and *₄ are eacha binding site to M, R₁ to R₈ are each independently selected fromhydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group,a nitro group, an amino group, an amidino group, a hydrazino group, ahydrazono group, a carboxylic acid group or a salt thereof, a sulfonicacid group or a salt thereof, a phosphoric acid group or a salt thereof,a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted orunsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstitutedC₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxygroup, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, asubstituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted orunsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted orunsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, asubstituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted orunsubstituted monovalent non-aromatic condensed polycyclic group, asubstituted or unsubstituted monovalent non-aromatic condensedheteropolycyclic group, —C(Q₁)(Q₂)(Q₃), —Si(Q₁)(Q₂)(Q₃), —B(Q₁)(Q₂),—N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁),—P(═O)(Q₁)(Q₂), and —P(═S)(Q₁)(Q₂), wherein adjacent groups from amongR₁ to R₈ are optionally bound to form a substituted or unsubstitutedC₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀heterocyclic group, adjacent groups from among R₁ to R₈ and Y₁ to Y₄ areoptionally bound to form a substituted or unsubstituted C₅-C₆₀carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclicgroup, b1 to b4 are each independently an integer from 0 to 10, and atleast one substituent of the substituted C₆-C₃₀ arylene group, thesubstituted C₁-C₃₀ heteroarylene group, the substituted C₁-C₆₀ alkylgroup, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substitutedC₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group,the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, thesubstituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group,the substituted C₁-C₆₀ heteroaryl group, the substituted monovalentnon-aromatic condensed polycyclic group, the substituted monovalentnon-aromatic condensed heteropolycyclic group, the substituted C₅-C₆₀carbocyclic group, and the substituted C₁-C₆₀ heterocyclic group isselected from: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, and a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenylgroup, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, eachsubstituted with at least one selected from deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amidino group, ahydrazino group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂),—B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenylgroup, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, amonovalent non-aromatic condensed polycyclic group, and a monovalentnon-aromatic condensed heteropolycyclic group; a C₃-C₁₀ cycloalkylgroup, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, aC₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxygroup, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),—B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ toQ₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl groupsubstituted with a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group substitutedwith a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, a biphenyl group, and a terphenylgroup, and * and *′ each indicate a binding site to an adjacent atom.10. The organic light-emitting device of claim 9, wherein the thirdcompound and the fourth compound are each independently selected fromcompounds represented by Formulae 1-1 and 1-2:

wherein, in Formulae 1-1 and 1-2, M, L₂, n1, n2, CY₁ to CY₄, Y₁ to Y₃,a1 to a3, T₁ to T₄, R₁ to R₄, and b1 to b4 are respectively understoodby referring to the descriptions of M, L₂, n1, n2, CY₁ to CY₄, Y₁ to Y₃,a1 to a3, T₁ to T₄, R₁ to R₄, and b1 to b4 in Formulae 1 and 1 Å to 1C.11. The organic light-emitting device of claim 1, wherein the thirdcompound is a compound represented by Formula 2-1, and the fourthcompound is a compound represented by Formula 2-2:

wherein, in Formulae 2-1 and 2-2, M₁ is Pt, M₂ is selected from afirst-row transition metal, a second-row transition metal, and athird-row transition metal, CY₁₂ to CY₁₄ and CY₂₂ to CY₂₄ are eachindependently selected from a C₅-C₃₀ carbocyclic group and a C₁-C₃₀heterocyclic group, A₁₁, A₁₂, A₂₁, and A₂₂ are each independently N orP, X₁₁ to X₁₃ and X₂₁ to X₂₃ are each independently N or C, Y₁₁ to Y₁₃are each independently selected from a single bond, a double bond, asubstituted or unsubstituted C₆-C₃₀ arylene group, a substituted orunsubstituted C₁-C₃₀ heteroarylene group, *—O—*′, *—S—*′, *—C(═O)—*′,*—S(═O)—*′, *—C(R₁₅)(R₁₆)—*′, *—C(R₁₅)═C(R₁₆)—*′, *—C(R₁₅)═*′,*—Si(R₁₅)(R₁₆)—*′, *—B(R₁₅)—*′, *—N(R₁₅)—*′, and *—P(R₁₅)—*′, Y₂₁ to Y₂₃are each independently selected from a single bond, a double bond, asubstituted or unsubstituted C₆-C₃₀ arylene group, a substituted orunsubstituted C₁-C₃₀ heteroarylene group, *—O—*′, *—S—*′, *—C(═O)—*′,*—S(═O)—*′, *—C(R₂₅)(R₂₆)—*′, *—C(R₂₅)═C(R₂₆)—*′, *—C(R₂₅)═*′,*—Si(R₂₅)(R₂₆)—*′, *—B(R₂₅)—*′, *—N(R₂₅)—*′, and *—P(R₂₅)—*′, a11 to a13are each independently selected from 1, 2, and 3, a21 to a23 are eachindependently selected from 1, 2, and 3, T₁₁ to T₁₄ are eachindependently selected from a chemical bond, *—O—*′, *—S—*′,*—B(R₁₇)—*′, *—N(R₁₇)—*′, *—P(R₁₇)—*′, *—C(R₁₇)(R₁₈)—*′,*—Si(R₁₇)(R₁₈)—*′, *—Ge(R₁₇)(R₁₈)—*′, *—C(═O)—*′, and *—C(═S)—*′, T₂₁ toT₂₄ are each independently selected from a chemical bond, *—O—*′,*—S—*′, *—B(R₂₇)—*′, *—N(R₂₇)—*′, *—P(R₂₇)—*′, *—C(R₂₇)(R₂₈)—*′,*—Si(R₂₇)(R₂₈)—*′, *—Ge(R₂₇)(R₂₈)—*′, *—C(═O)—*′, and *—C(═S)—*′,R_(11a) to R_(11c), R₁₂ to R₁₈, R_(21a) to R_(21c), and R₂₂ to R₂₈ areeach independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I,a hydroxyl group, a cyano group, a nitro group, an amino group, anamidino group, a hydrazino group, a hydrazono group, a carboxylic acidgroup or a salt thereof, a sulfonic acid group or a salt thereof, aphosphoric acid group or a salt thereof, a substituted or unsubstitutedC₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group,a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted orunsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylgroup, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, asubstituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, asubstituted or unsubstituted C₆-C₆₀ aryl group, a substituted orunsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstitutedC₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroarylgroup, a substituted or unsubstituted monovalent non-aromatic condensedpolycyclic group, a substituted or unsubstituted monovalent non-aromaticcondensed heteropolycyclic group, —C(Q₁)(Q₂)(Q₃), —Si(Q₁)(Q₂)(Q₃),—B(Q₁)(Q₂), —N(Q₁)(Q₂), —P(Q₁)(Q₂), —C(═O)(Q₁), —S(═O)(Q₁), —S(═O)₂(Q₁),—P(═O)(Q₁)(Q₂), and —P(═S)(Q₁)(Q₂), wherein adjacent groups from amongR_(11a) to R_(11c) and R₁₂ to R₁₈ are optionally bound to form asubstituted or unsubstituted C₅-C₆₀ carbocyclic group or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group, and adjacent groups fromamong R_(21a) to R_(21c) and R₂₂ to R₂₈ are optionally bound from asubstituted or unsubstituted C₅-C₆₀ carbocyclic group or a substitutedor unsubstituted C₁-C₆₀ heterocyclic group, b12 to b14 and b22 to b24are each independently an integer from 0 to 10, and at least onesubstituent of the substituted C₆-C₃₀ arylene group, the substitutedC₁-C₃₀ heteroarylene group, the substituted C₁-C₆ alkyl group, thesubstituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group,the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkylgroup, the substituted C₁-C₁₀ heterocycloalkyl group, the substitutedC₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenylgroup, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxygroup, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀heteroaryl group, the substituted monovalent non-aromatic condensedpolycyclic group, the substituted monovalent non-aromatic condensedheteropolycyclic group, the substituted C₅-C₆₀ carbocyclic group, andthe substituted C₁-C₆₀ heterocyclic group is selected from: deuterium,—F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, anamidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkylgroup, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at leastone selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, aC₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆heteroaryl group, a monovalent non-aromatic condensed polycyclic group,a monovalent non-aromatic condensed heteropolycyclic group,—Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁),—S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group; a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, and a monovalent non-aromaticcondensed heteropolycyclic group, each substituted with at least oneselected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyanogroup, a nitro group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, aC₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂),—B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁),—S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), wherein Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ toQ₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen,deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitrogroup, an amino group, an amidino group, a hydrazino group, a hydrazonogroup, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynylgroup, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl groupsubstituted with a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group substitutedwith a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalentnon-aromatic condensed polycyclic group, a monovalent non-aromaticcondensed heteropolycyclic group, a biphenyl group, and a terphenylgroup, and * and *′ each indicate a binding site to an adjacent atom.12. The organic light-emitting device of claim 11, wherein, in Formula2-1, at least one selected from R_(11a) to R_(11c) and R₁₄ is anelectron-donating group, and in Formula 2-2, i) at least one selectedfrom R₂₂ and R₂₃ is a substituent other than hydrogen, ii) Y₂₃ is*—N(R₂₅)—*′, and R₂₅ is a substituted C₆-C₆₀ aryl group, or iii) atleast one selected from R₂₂ and R₂₃ is a substituent other thanhydrogen, Y₂₃ is *—N(R₂₅)—*′, and R₂₅ is a substituted C₆-C₆₀ arylgroup.
 13. The organic light-emitting device of claim 12, wherein theelectron-donating group is a substituent selected from an iso-propylgroup, a tert-butyl group, and groups represented by Formulae 10-1 to10-61:

wherein, in Formulae 10-1 to 10-61, “i-Pr” represents an iso-propylgroup, “t-Bu” represents a t-butyl group, “Ph” represents a phenylgroup, and * indicates a binding site to an adjacent atom.
 14. Theorganic light-emitting device of claim 11, wherein the third compound isan organometallic compound represented by Formula 2-1 Å or Formula 2-1B,and the fourth compound is an organometallic compound represented byFormula 2-2A:

wherein in Formulae 2-1A, 2-1B, and 2-2A, Z₁₁ is C(R_(12a)) or N, Z₁₂ isC(R_(12b)) or N, Z₁₃ is C(R_(12c)) or N, Z₁₄ is C(R_(13a)) or N, Z₁₅ isC(R_(13b)) or N, Z₁₆ is C(R_(13c)) or N, Z₁₇ is C(R_(14a)) or N, Z₁₈ isC(R_(14b)) or N, Z₁₉ is C(R_(14c)) or N, Z₂₀ is C(R_(14d)) or N, Z₃₁ isC(R_(15a)) or N, Z₃₂ is C(R_(15b)) or N, Z₃₃ is C(R_(15c)) or N, and Z₃₄is C(R_(15d)) or N, Z₂₁ is C(R_(22a)) or N, Z₂₂ is C(R_(22b)) or N, Z₂₃is C(R_(22c)) or N, Z₂₄ is C(R_(23a)) or N, Z₂₅ is C(R_(23b)) or N, Z₂₇is C(R_(24a)) or N, Z₂₈ is C(R_(24b)) or N, Z₂₉ is C(R_(24c)) or N, Z₃₀is C(R_(24d)) or N, Z₄₁ is C(R_(25a)) or N, Z₄₂ is C(R_(25b)) or N, Z₄₃is C(R₂₅ c) or N, and Z₄₄ is C(R_(25d)) or N, R_(12a) to R_(12c) areeach understood by referring to the description of R₁₂ in Formula 2-1,R_(13a) to R_(13c) are each understood by referring to the descriptionof R₁₃ in Formula 2-1, R_(14a) to R_(14d) are each understood byreferring to the description of R₁₄ in Formula 2-1, R_(15a) to R_(15d)are each understood by referring to the description of R₁₅ in Formula2-1, R_(22a) to R_(22c) are each understood by referring to thedescription of R₂₂ in Formula 2-2, R_(23a) to R_(23c) are eachunderstood by referring to the description of R₂₃ in Formula 2-2,R_(24a) to R_(24d) are each understood by referring to the descriptionof R₂₄ in Formula 2-2, R_(25a) to R_(25d) are each understood byreferring to the description of R₂₅ in Formula 2-2, and M₁, M₂, CY₁₂ toCY₁₄, CY₂₂ to CY₂₄, A₁₁, A₁₂, A₂₁, A₂₂, X₁₁ to X₁₃, X₂₁ to X₂₃, Y₁₁ toY₁₃, Y₂₁ to Y₂₃, a11 to a13, a21 to a23, T₁₁ to T₁₄, T₂₁ to T₂₄, R_(11a)to R_(11c), and R_(21a) to R_(21c) are respectively understood byreferring to the descriptions of M₁, M₂, CY₁₂ to CY₁₄, CY₂₂ to CY₂₄,A₁₁, A₁₂, A₂₁, A₂₂, X₁₁ to X₁₃, X₂₁ to X₂₃, Y₁₁ to Y₁₃, Y₂₁ to Y₂₃, a11to a13, a21 to a23, T₁₁ to T₁₄, T₂₁ to T₂₄, R_(11a) to R_(11c), andR_(21a) to R_(21c) in Formulae 2-1 and 2-2.
 15. The organiclight-emitting device of claim 1, wherein the total content of the thirdcompound and the fourth compound is in a range of about 1 percent byvolume (vol %) to about 50 vol %, based on the total volume of the firstcompound and the second compound in the emission layer.
 16. The organiclight-emitting device of claim 1, further comprising a capping layer onthe second electrode, wherein the capping layer has a refractive indexof 1.6 or greater at a wavelength of 589 nanometers (nm).
 17. Theorganic light-emitting device of claim 1, wherein the emission layercomprises a first emission layer and a second emission layer, the firstemission layer is between the first electrode and the second emissionlayer, the first emission layer comprises the first compound, the secondcompound, and a first dopant, the second emission layer comprises thefirst compound, the second compound, and a second dopant, the firstdopant is one selected from the third compound and the fourth compound,and the second dopant is different from the first dopant and is theother one selected from the third compound and the fourth compound. 18.The organic light-emitting device of claim 17, wherein a differencebetween a maximum emission wavelength of light emitted from the firstemission layer and a maximum emission wavelength of light emitted fromthe second emission layer is in a range of about 0 nm to about 35 nm.19. The organic light-emitting device of claim 1, wherein the emissionlayer comprises a first emission layer, a second emission layer, and athird emission layer, the first emission layer is between the firstelectrode and the second emission layer, the second emission layer isbetween the first electrode and the third emission layer, the firstemission layer comprises the first compound, the second compound, and afirst dopant, the second emission layer comprises the first compound,the second compound, and a second dopant, the third emission layercomprises the first compound, the second compound, and a third dopant,the first dopant and the third dopant are each one selected from thethird compound and the fourth compound, and the second dopant isdifferent from the first dopant and the third dopant and is the otherone selected from the third compound and the fourth compound.
 20. Anelectronic apparatus comprising: a thin-film transistor comprising asource electrode, a drain electrode, and an active layer; and theorganic light-emitting device of claim 1, wherein the first electrode ofthe organic light-emitting device is electrically coupled to any oneselected from the source electrode and the drain electrode of thethin-film transistor.